JP2000033633A - Valve gate unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To unify a plurality of valve gates and a manifold to easily mount them on an injection mold and to perform work, for example, in the replacement of a material or a color within a short time to enhance productivity. SOLUTION: A valve gate unit 10 is equipped with the unit body 13 (block body) detachable to the housing recessed part 17a of the movable mold 17 of an injection mold, a plurality of the valve gates 1, 2 respectively provided to the unit body 13 to supply a molten resin to a plurality of the cavities K, K of the injection mold and the manifold 14 provided in the unit body 13 to supply the molten resin injected from an injection molding machine to the valve gates 1, 2. That is, the valve gate unit 10 is unified by mounting a plurality of the valve gates 1, 2 and the manifold 14 on the unit body 13 detachable to the movable mold 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve gate which is a kind of hot runner gate system in an injection mold.

[0002]

2. Description of the Related Art In general, a valve gate of this type is provided with a heater (for example, a band heater) mounted on an outer peripheral surface of a cylinder having a resin passage, and the resin passage of the cylinder heated by the heater. The molten resin passes through the inside, and the molten resin is injected into the cavity of the injection mold or the injection is interrupted. In this injection mold, one valve gate is usually arranged for each cavity of the injection mold, and a manifold for supplying molten resin to each valve gate is provided.
Each valve gate and manifold are not unitized, but are individually mounted on the movable mold of the injection mold.
The movable mold has a cooling water passage for cooling the molten resin in each cavity.

[0003]

As described above, since each of the valve gates and the manifold is individually mounted on the injection mold, it takes time to mount the valve gate and the manifold. In particular, for example, when changing materials or changing colors, each valve gate and manifold must be individually removed from the injection molding die or separately mounted, which requires a long time for setup and increases productivity. Lower. In addition, maintenance and parts management become complicated. In addition, providing a cooling water passage having a complicated path on the movable mold side also increases the mold manufacturing cost.

The present invention has been made in view of the above-mentioned problems of the prior art, and has been made by, for example, making a plurality of valve gates and a manifold unit detachable from an injection mold so that, for example, material change is possible. It is an object of the present invention to provide a valve gate unit capable of performing setup for color change and color change in a short time and improving productivity. Another object of the present invention is to provide a valve gate unit which does not need to provide a complicated cooling water passage in a movable mold and can reduce a mold cost.

[0005]

In order to achieve the above object, a valve gate unit according to the present invention is provided with a unit main body that can be attached to and detached from a concave portion formed in a movable die of an injection mold, and provided in the unit main body. And a manifold into which the molten resin is injected from the injection molding machine, and a plurality of the plurality of molds respectively mounted on the unit main body and capable of injecting the molten resin supplied from the manifold into the plurality of cavities of the injection mold. And a valve gate. As described above, in the valve gate unit of the present invention, the plurality of valve gates and the manifold are mounted on the unit body to form a unit, and this can be easily mounted on a movable mold.

According to another aspect of the present invention, the unit main body is provided with a plurality of cooling jackets each having an annular passage surrounding each valve gate, and the unit main body is further provided with the annular passage of each cooling jacket. A cooling water passage for supplying cooling water to the cooling unit and guiding cooling water discharged from each cooling jacket to the outside of the unit body. In the present invention, by providing the cooling means in the unit main body, it is not necessary to provide a cooling water passage having a complicated path as in the related art in the mold.

Further, another invention is that the unit main body is provided with a guide pin which is guided by a retainer provided on the movable die when the unit main body is mounted on the movable side. is there. In the present invention, when the valve gate unit is mounted on the movable type, the guide pins of the unit body are guided by the movable retainer, so that the mounting can be performed easily and with high precision.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of an injection mold provided with one embodiment of the valve gate unit of the present invention, and FIG. 2 is a view of the valve gate unit shown in FIG. 1 as viewed from below. In FIG. 1, the center axis of the right valve gate 2 and the center axis of the resin supply pipe 20 are coincident with each other. Is located symmetrically with respect to the valve gate 1.

As shown in FIGS. 1 and 2, first, the main components of this valve gate unit 10 are an upper body (upper block) 11 and a lower body (lower block) 12
And a plurality of units (blocks in this example) mounted on the lower body 12 of the unit body 13 for supplying molten resin to the plurality of cavities K of the injection mold. And (2) valve gates 1 and 2 (refer to FIG. 3) and a molten resin injected from an injection molding machine (not shown) built in the unit main body 13 to supply to each of the valve gates 1 and 2. Manifold 14
And a plurality (two in this example) of cooling jackets 15 and 16 mounted on the lower body 12 of the unit body 13 and surrounding the valve gates 1 and 2, respectively.

The valve gate unit 10 includes a unit housing recess 17 formed in a movable mold 17 of an injection mold.
a. The molten resin injected from the injection molding machine (not shown) is supplied to a resin supply pipe 20.
Is once supplied into the manifold 14 through the
Through the two valve gates 1 and 2, each cavity K,
K is to be injected. The unit main body 13 is fixed to the movable die 17 by a holding plate 100 attached to the movable die 17 by screws 101.

The detailed structure of each part will be described below.
The lower body 12 of the unit body 13 is formed with a manifold accommodating recess 21 opening on the upper surface thereof,
Two valve gate through-holes 22 and 23 communicating with the manifold accommodating recess 21 are formed. A manifold 14 is accommodated in the manifold accommodating recess 21, and the molten resin injected from the injection molding machine (not shown) is supplied to the resin passage 1 in the manifold 14.
A resin supply pipe 20 for supplying the resin 4a is fixed by a bolt 24 or the like. The one indicated by reference numeral 25 is
A heater provided on the outer peripheral portion of the manifold 14 for heating is shown. The molten resin supplied into the manifold 14 is supplied to resin passages 3 and 3 of each of the valve gates 1 and 2 described later.

The upper main body 11 is fixed to the lower main body 12 with bolts 26 or the like and is integrated therewith. The upper main body 11 is formed with a through hole 27 for inserting the resin supply pipe 20. The upper body 22 has two valve pins 28 and 29, which will be described later, and two valve pins 28 and 29 for driving the valve pins 28 and 29 in the vertical direction to open and close the resin passages 3 and 3 of the respective valve gates 1 and 2. Pistons 30, 31 and the like are provided. A guide pin 32 projecting downward is fixed to the lower body 12, while a through hole 34 that accommodates a ball retainer 33 for guiding the guide pin 32 is formed in the movable mold 17. .

When the valve gate unit 10 of this embodiment is mounted in the unit housing recess 17a of the movable die 17 (the state shown in FIG. 1), the lower end of the guide pin 32
It is inserted into a hole 35 formed in the fixed die 18. The ball retainer 3 is provided at the lower end of the guide pin 32.
Flange member 36 for preventing falling off 3 is screw 37
It is fixed by. With such a configuration, when the valve gate unit 10 is mounted on the movable mold 17, the injection gate is open (the parting line is indicated by the symbol PL), and the valve gate unit 10 is mounted. The guide pins 32 are lowered while the guide pins 32 are guided by the ball retainers 33, so that they can be mounted easily and with high positional accuracy. Thereafter, the flange member 36 is attached to the guide pin 32.

The two valve gate through holes 2 in the lower body 12
Valve gates 1 and 2 respectively penetrate through 2 and 23,
The upper flange portions 6 of the valve gates 1 and 2 are locked to peripheral edges of the valve gate through holes 22 and 23 and fixed by screws (not shown) or the like. The upper flange 6 of each of the valve gates 1 and 2 is also fixed to the manifold 14.

Here, the detailed structure of the valve gates 1 and 2 will be described. Since the two valve gates 1 and 2 have the same structure, one valve gate 1 will be described here as an example. Housing 1a of this valve gate 1
Has a resin passage 3 in which an upper part of a cylindrical main body part 4 is integrally formed with a flange part 6 which is a fixing part to an injection mold (not shown). A plurality of bolt holes (not shown) are formed in the outer peripheral portion of the flange portion 6, and are fixed to the lower main body 12 by screws (not shown) passing through the bolt holes (not shown). The resin passage 3 is provided in the housing 1a.
And a curved portion 3b connected to the upper end thereof, and a valve pin 28 (see FIG. 1) is inserted into the straight portion 3a. The valve pin 28 (see FIG. 1) is connected to the cylindrical guide member 8 fixed to the flange 6.
Slidably penetrates the pin hole 8a. Further, the valve pin 28 (see FIG. 1) is moved up and down by a piston 30, which will be described later, and when the lower end of the valve pin 28 (see FIG.
Closes.

On the outer peripheral surface of the main body 4 of the housing 1a,
The heater 5 is uniformly wound in the circumferential direction.
Accordingly, the housing 1a is heated, and the resin in the resin passage 3 is always in a molten state. The temperature of the housing 1a is detected by a thermocouple 9, and this detection signal is guided to a predetermined device (not shown) through the electric wire 7 or the like.

As shown in FIGS. 1 and 2 again, the main body 4 of each of the valve gates 1 and 2 is surrounded by substantially cylindrical cooling jackets 15 and 16. Cooling jacket 1
The upper and lower flange portions 40 are fixed to the lower main body 12 by screws 41. A cooling water passage 42 is formed in an annular shape below the cooling jacket 15. The cooling jacket 15 is provided with a cooling water supply port 43 and a cooling water discharge port 44 at positions different from the upper flange portion 40 by 180 degrees in the circumferential direction.
The cooling water discharge port 44 communicates with the annular passage 42 via passages 45 and 46, respectively.

With such a configuration, the cooling water introduced into the cooling water supply passage 47a of the movable mold 17 is first introduced into the cooling water passage 48a of the lower main body 12, and further cooled through the cooling water supply port 43. The cooling water enters the passage 45 in the jacket 15 and is introduced into the annular cooling water passage 42. The cooling water is guided to the cooling water discharge port 44 through the passage 46, and the cooling water passage 48 b of the lower main body 12 and It is discharged out of the mold by sequentially passing through a discharge passage (not shown) of the movable mold 17.
In addition, the cooling water can be supplied to the cooling jacket 16 of the other valve gate 2 in the same manner. The molten resin injected into the cavity K can be cooled by the cooling water flowing in the annular cooling water passage 42.

The upper main body 12 is provided with pistons 30 and 31 for driving the valve pins 28 and 29, respectively. Further, pressure oil passages 50 and 51 for driving the pistons 30 and 31 are provided in the upper main body 12. 12 are formed. The upper body 12 is moved from one pressure oil passage 52 of the movable side 17.
When pressure oil is supplied to one of the passages 50, each piston 3
0 and 31 are lowered, and the valve pins 28 and 29 can be lowered synchronously.
Accordingly, when the pressure oil is supplied to the other passage 51 of the upper main body 12, each of the pistons 30, 31 rises, and the valve pins 28,
19 can be raised synchronously.

The valve gate unit 10 of the present embodiment
Since the plurality of valve gates 1 and 2 and the manifold 12 are mounted on the unit body 13 to form a unit, these can be easily mounted on the movable mold 17 collectively. In addition, for example, in the case of material change or color change, each valve gate 1, 2 and the manifold 14 as in the related art do not have to be individually removed from the injection molding die or to be separately mounted,
Setup can be performed in a short time, and the productivity of injection molding is greatly improved.

The valve gate unit 10 is provided with the cooling jackets 15, 16 and their cooling water passages 48a, 48b.
Therefore, there is no need to provide a complicated cooling water passage on the mold side, and the valve gate unit 10
Is a pressure oil passage 5 for driving the valve pins 28 and 29.
Since there are 0 and 51, there is no need to provide a pressure oil passage having a complicated path on the mold side. Therefore, the mold cost is significantly reduced. In addition, the ball retainer 3 provided on the movable die 17 of the injection molding die is provided on the unit body 13.
By protruding the guide pin 32 guided to 3,
The valve gate unit 10 can be easily mounted on the movable mold 17 while being positioned with high precision.

In the above embodiment, a valve gate unit having two valve gates has been described as an example. However, the number of valve gates may be another number.

[0023]

According to the valve gate unit of the present invention described above, a plurality of valve gates and a manifold are mounted on a unit body to form a unit, and these are easily mounted and removed collectively on a movable mold. it can. In addition, for example, when changing materials or changing colors, each valve gate and manifold as in the conventional case does not have to be individually removed from the injection mold or attached separately, so setup can be performed in a short time, and productivity can be improved. Is improved. Further, maintenance and parts management of the valve gate unit are also facilitated.

Further, by providing the cooling means in the unit body, it is not necessary to provide a cooling water passage having a complicated path as in the prior art, and the cost of the mold is greatly improved. Furthermore, by mounting a guide pin, which is guided by a retainer provided on the movable mold of the injection mold, on the unit body, when the movable mold is mounted on the valve gate unit,
Since the guide pins of the unit body are guided by the movable retainer, the mounting can be performed easily and with high accuracy.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an injection mold provided with an embodiment of a valve gate unit of the present invention, wherein a center axis of a valve gate on the right side and a center axis of a resin supply pipe coincide with each other. Actually, the right valve gate is located symmetrically with the left valve gate about the resin supply pipe.

FIG. 2 is a view of the valve gate unit of FIG. 1 as viewed from below.

FIG. 3 is an enlarged sectional view of the valve gate shown in FIG.

[Explanation of symbols]

 K cavity 1, 2 Valve gate 1a Valve gate housing 10 Valve gate unit 13 Unit body 14 Manifold 15, 16 Cooling jacket 32 Guide pin 33 Ball retainer 42 Annular passage 48a, 48b Cooling water passage

Claims (3)

[Claims] 1. A unit body detachable from a concave portion formed in a movable mold of an injection mold, a manifold provided in the unit body, and into which molten resin is injected from an injection molding machine, and the unit body And a plurality of valve gates respectively mounted on the injection mold and capable of injecting the molten resin supplied from the manifold into the plurality of cavities of the injection mold. 2. The unit main body is provided with a plurality of cooling jackets each having an annular passage around each valve gate, and further supplies cooling water to the unit main body through the annular passage of each cooling jacket. 2. The valve gate unit according to claim 1, wherein a cooling water passage for guiding cooling water discharged from each cooling jacket to outside of the unit main body is formed. 3. The unit body is provided with a guide pin which is guided by a retainer provided on the movable mold when the unit body is mounted on the movable side. The described valve gate unit.