JPH07290518A - Method and device for opening/closing injection opening of hot runner nozzle - Google Patents

Abstract

PURPOSE:To change color of resin and replace material without problem, facilitate maintenance, and improve uniformity of a molded piece by decentering an injection opening of a nozzle, providing a hole in a position of an opposite member conforming to the injection opening, and rotating the nozzle or the opposite member. CONSTITUTION:A nozzle is provided for a hot runner to be used in an injection molding device. An injection opening 24 of a hot runner nozzle 21 is arranged at a position decentered from the central part of the hot runner nozzle 21. In a cap 25, a hole 31 is provided at a position conforming to the injection opening 24 of the hot runner nozzle 21 and is rotatably attached to the tip of the hot runner nozzle 21 by fittings 26. At the cap 25, an arm 27 for rotating the cap 25 is provided. To the arm 27, a piston rod 29 of a cylinder 28 to be driven hydraulically is connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for opening and closing a nozzle of a hot runner of an injection molding machine.

[0002]

2. Description of the Related Art Conventionally, for example, plastic molding technology No. 9
As a system for opening and closing a nozzle of a hot runner of an injection molding apparatus, which is known as a separate volume of Volume 12, a needle is provided in the nozzle and the needle is slid by an ON / OFF means such as an electromagnetic solenoid provided outside. The nozzle injection part was opened and closed by moving the nozzle.

[0003]

In the above-described conventional example, the loss of injection pressure is large because the needle is arranged in the resin flow passage. In addition, since the injection resin adheres to the needle inside the resin flow passage, it is difficult to change the color of the resin or replace it with a different type of resin, and a thermally unstable resin will not decompose or discolor. Occur. Also,
Since the needle is operated from the outside into the resin passage to which a high pressure is applied, sealing is difficult and maintenance is complicated and difficult. In addition, since the needle is slid to open and close the nozzle injection part, when the nozzle injection part is closed, the resin remaining in the nozzle injection part is pushed into the cavity side, adversely affecting the molded product. .

In view of this, the present invention has a method for opening and closing the injection port of a hot runner nozzle by a simple method, and a device for opening and closing the injection port of a hot runner nozzle that is easy to maintain and has no problem in resin color change. It was made for the purpose.

[0005]

In order to achieve the above object, a first aspect of the present invention is a nozzle for a hot runner used in an injection molding apparatus, in which the injection port of the nozzle is eccentric from the center of the nozzle. And a hole is provided at a position corresponding to the injection port of the facing member, and the injection port of the hot runner nozzle is opened and closed by rotating the nozzle or the facing member, and the second invention is In a nozzle for a hot runner used in an injection molding apparatus, an injection port of the nozzle is provided eccentrically from the center of the nozzle, a rotatable cap is provided at the tip of the nozzle, and the cap has the injection port of the nozzle. A hot runner nozzle opening / closing device for a hot runner nozzle, characterized in that a hole is provided at a position corresponding to the hot runner nozzle. In the nozzle for the nozzle, the nozzle is provided rotatably with respect to the mold, the injection port of the nozzle is provided eccentrically from the central part of the nozzle, and a hole corresponding to the injection port of a member facing the nozzle is provided. A hot-runner nozzle opening / closing device for the hot runner nozzle.

[0006]

According to the above structure, in the first aspect of the invention, the nozzle outlet is provided eccentrically from the center of the nozzle, and the hole is provided at a position corresponding to the outlet of the facing member. By rotating the nozzle, the positional relationship between the nozzle outlet and the hole provided in the member shifts, and the outlet can be opened and closed. In the second invention, the rotatable cap is provided at the tip of the nozzle. The external drive means allows the opening to be opened and closed by shifting the positional relationship between the hole provided in the cap and the injection port. Further, in the third invention, the nozzle is provided rotatably, and By providing the holes in the members facing each other, by rotating the nozzle by the external driving means, the positional relationship between the ejection opening of the nozzle and the hole provided in the member is deviated, and the ejection opening can be opened and closed.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a hot runner nozzle in which a needle is arranged in a conventional nozzle. The hot runner nozzle 1 is fixedly installed in the molds 2a and 2b and slidable in the hot runner nozzle 1. A needle 3 is provided. The upper end of the needle 3 is connected to an actuator 4, the actuator 4 is driven by a hydraulic power source (not shown), and 5 and 6 are inflow passages from the hydraulic power source. The lower end of the needle 3 has the same diameter as that of the injection port 7 of the nozzle 1. When a predetermined amount of resin flows into the cavity 10 provided in the movable mold 9 through the resin inflow passage 8, Oil flows into the inflow passage 5, the actuator 4 is pushed down, and the needle 3 connected thereto is lowered to close the injection port 7. FIG. 2 is an enlarged view of the injection port 7 of the nozzle 1 and the needle 3
Is lowered, the injection port 7 and the lower end of the needle are engaged, and the injection port 7
Is shown in a closed state, and FIG. 3 shows a state in which the injection port 7 is opened.

FIG. 4 relates to the first and second inventions, and shows the structure of a hot runner nozzle provided in the mold of an injection molding machine. Fixed type 20a, 20
A hot runner nozzle 21 is attached to the inside of b, and an induction heating coil 30 is wound around the hot runner nozzle. By applying a high frequency current to the induction heating coil 30 from a control device (not shown), electromagnetic induction is generated. The hot runner nozzle 21 is heated to melt the resin in the hot runner nozzle. The fixed mold 20a,
In the state in which the movable die 22 located at a position corresponding to 20b is engaged, the resin flows from the hot runner nozzle 21 into the cavity 23.
It is injected inside.

The injection port 24 of the hot runner nozzle 21 is arranged at a position eccentric from the center of the hot runner nozzle 21, and the cap 25 has a hole 31 at a position corresponding to the injection port 24 of the hot runner nozzle 21. Is provided and is rotatably attached to the tip of the hot runner nozzle 21 by an attachment 26. Cap 2
5 includes an arm 27 for rotating the cap 25.
Is provided, and a piston rod 29 of a cylinder 28 hydraulically driven is connected to the arm 27.
The cylinder 28 slides in the left-right direction by the inflow of oil from the oil inlets 49, 50.

FIG. 5 is a view showing the attachment and operation of the hot runner nozzle 21 and the cap 25. When the cap 25 is pushed and pulled by the piston rod 29, the cap 25
Rotates left and right. At this time, since the hole 31 provided in the cap 25 is provided at a position corresponding to the eccentric injection port 24 of the hot runner nozzle 21, the cap 2
The rotation of 5 to the left shifts the positional relationship between the ejection port 24 and the hole 31, and the ejection port 24 is closed by the cap 25. The rotation to the right direction causes the ejection port 24 and the hole 31 of the cap 25. The positions are matched and the injection port is opened.

In order to ensure the positioning of the cap 25 in the open state, the cap 25 is provided with a groove portion 32, and a stopper portion 34 provided in a part of the fixture 26 is engaged with the groove portion 32. It is good to do so. FIG. 6 shows a state in which the cap 25 is rotated.
The positional relationship between the hole 31 and the injection port 24 provided at the position is shifted and the injection port 24 is closed. FIG. 7 shows an outlet 24
Shows the opened state. The hole 31 provided in the cap 25 is formed in a tapered shape in consideration of the inflow of resin into the cavity 23, and the surface on the cavity 23 side is formed wide.

FIG. 8 relates to the first and third aspects of the invention. A hot runner nozzle 36 is rotatably provided by a receiving member 37 in the fixed molds 35a and 35b of the mold of the injection molding machine. In this invention, the hot runner nozzle 3
The induction heating coil 51 is provided apart from the hot runner nozzle 36 in order to rotate the coil 6. Fixed type 35
A movable die 52 is arranged at a position facing a and 35b, and a cavity 53 is formed in the movable die. Further, a member 40 having a hole 39 provided at a position corresponding to the injection port 38 of the hot runner nozzle 36 is detachably provided at the tip of the hot runner nozzle 36, and as shown in FIG. The flange portion 41 provided on the member 40 engages with the groove portion 42 provided on the fixed mold 35b so as not to rotate together with the rotation of the hot runner nozzle 36.

An arm 44 is movably attached to a rotating member 43 provided on the hot runner nozzle 36, and a piston rod 46 of a hydraulically driven cylinder 45 is connected to the arm 44. With such a configuration, when oil flows into the oil inlet 47 of the cylinder 45, the cylinder 45 is moved leftward, the piston rod 46 is moved leftward, and the hot runner nozzle 36 is rotated leftward. As a result, the positional relationship between the injection port 38 of the hot runner nozzle 36 and the hole 39 provided in the member 40 is deviated, and the injection port 38 can be closed. Further, in order to open the injection port 38, oil may be made to flow into the oil inflow passage 48 side.

In the above description, the structure in which the member 40 is detachable has been described. However, the structure is not limited to this, the member may be fixed, and a hole is provided in the mold 35a at a position corresponding to the injection port. Is also good. Further, in the above description, the external drive means is described as a hydraulically driven cylinder, but a linear actuator of a direct drive type or an electromagnetic solenoid can be used.

[0015]

With the above-mentioned structure, the opening and closing of the injection port can be configured with a simple mechanism. Since there is no need for any driving means in the nozzle, there is little pressure loss, and it is possible to change the color of the resin or the material. On the other hand, there is no problem, and maintenance can be performed easily. Further, since the pressure applied by the nozzle injection port after injection is eliminated for the molded product, the molded product can be molded uniformly. Further, in the invention in which the detachable member is provided, it is possible to easily replace the member even if the member is worn down by the rotation of the nozzle.

[Brief description of drawings]

FIG. 1 is a view showing a conventional injection port opening / closing mechanism of a hot runner nozzle.

FIG. 2 is a view showing a state in which the nozzle of FIG. 1 is closed.

FIG. 3 is a diagram showing a state in which the nozzle of FIG. 1 is open.

FIG. 4 is an overall configuration diagram showing first and second embodiments according to the present invention.

5 is a perspective view of a hot runner nozzle tip portion of FIG. 4. FIG.

FIG. 6 is a view in which the injection port of FIG. 4 is closed.

FIG. 7 is a view in which the injection port of FIG. 4 is opened.

FIG. 8 is an overall configuration diagram showing first and third embodiments according to the present invention.

9 is a perspective view of the hot runner nozzle section of FIG. 8. FIG.

[Explanation of symbols]

20a, 20b Fixed type 21 Hot runner nozzle 22 Movable type 23 Cavity 24 Injection port 25 Cap 26 Fixture 27 Arm 28 Cylinder 29 Piston rod 30 Induction heating coil 31 Hole 32 Groove part
34 Stopper part 37 Receiving tool 40 Member 41 Collar part

Claims (6)

[Claims] 1. A nozzle for a hot runner used in an injection molding apparatus, wherein an injection port of the nozzle is eccentric from a central part of the nozzle, and a hole is provided at a position corresponding to the injection port of a facing member. A method of opening and closing the injection port of a hot runner nozzle by rotating opposing members. 2. A nozzle for a hot runner used in an injection molding apparatus, wherein an injection port of the nozzle is provided eccentrically from a central portion of the nozzle, a rotatable cap is provided at a tip end portion of the nozzle, and the cap is provided on the cap. An opening / closing device for an injection opening of a hot runner nozzle, characterized in that a hole is provided at a position corresponding to the injection opening of the nozzle. 3. A nozzle for a hot runner used in an injection molding apparatus, wherein the nozzle is provided so as to be rotatable with respect to a mold, and the injection port of the nozzle is provided eccentrically from the center of the nozzle, An opening / closing device for an injection port of a hot runner nozzle, characterized in that a hole is provided at a position corresponding to the injection port of a facing member. 4. The injection port opening / closing device for a hot runner nozzle according to claim 2, wherein the cap is rotated by an external drive means. 5. The opening / closing device for an injection opening of a hot runner nozzle according to claim 3, wherein the nozzle is rotated by an external driving means. 6. The injection port opening / closing device for a hot runner nozzle according to claim 3, wherein the member is a member that is mounted on a mold side having a nozzle and is removable.