JP5930741B2 - Split valve pin - Google Patents

Description

The present invention relates to a split Barubupi down for opening and closing a gate leading to a cavity of a mold in synthetic resin injection molding apparatus.

  In general, a relatively long valve pin is widely known as a means for opening and closing a gate of a cavity formed in a mold of various thermoplastic injection molding apparatuses.

  A piston is provided at the head of the valve pin, and is housed in a cylinder provided in the mold. The piston is reciprocated in the cylinder by an operating pressure of fluid such as hydraulic pressure or air pressure, and a cavity is formed at the tip pin portion. The gate is opened and closed to mold the molten resin (see, for example, Patent Document 1).

  Furthermore, a molding apparatus is also known in which a cam mechanism is incorporated in the head of a valve pin so that the valve pin is reciprocated to open and close the gate of the cavity (for example, see Patent Document 2).

JP-A-6-182815 JP 2001-170977 A

  By the way, the above-mentioned valve pin penetrates the manifold from the piston of the mounting plate and is inserted into the valve body to open and close the gate. Therefore, if the dimensions of the valve / spacer block, etc. change, a pin that requires high accuracy is manufactured. There must be. In order to remove the mounting plate, it is necessary to pull out the valve pin, but since the valve penetrates the synthetic resin of the molding raw material, the solidified synthetic resin of the raw material will not soften unless the valve is heated. There was a problem that it was difficult to pull out.

  Furthermore, depending on the size of the molded product or the size type of the multi-cavity molding machine, there is a problem that it is impossible to mass-produce a large number of different types of valve pins that require high accuracy in advance. It was.

The present invention has been made paying attention to the above points. The valve pin itself is divided into a piston cylinder mechanism, a valve pin upper part that operates by a reciprocating drive means such as a cam lever mechanism, and a valve pin lower part that opens and closes the gate. can be assembled composition was produced separately each Te, and an object thereof is to provide a split type Barubupi down.

  Below, the structure of this invention for solving the said subject is demonstrated.

(1) Valve pins used for injection molding operation, wherein an upper valve pin and a lower valve pin that are reciprocally driven are formed separately, arranged in a straight line, and inserted into the manifold, and a lower valve pin head And a coil spring interposed between the head of the lower valve pin and the flange of the insertion tube so as to be able to reciprocate via the coupling mechanism, and the coupling mechanism is attached to the valve body. Upper and lower ring-shaped stoppers that are threadedly engaged with the grooves provided on the inner periphery of the recessed portion provided in the recesses are arranged at intervals, and the flange formed on the head of the lower valve pin slides only between the stoppers. A split-type valve pin characterized by being movable .

According to the present invention, since the valve pin configuration configured to be long can be divided into two parts, the upper valve pin and the lower valve pin, and manufactured separately, the composition can be shortened. Can be manufactured.
The connection mechanism that connects the upper valve pin and the lower valve pin is such that the head of the lower valve pin and the lower end of the upper valve pin are located at the recessed portion that expands into the opening of the insertion hole of the valve body that is in contact with the lower portion of the manifold. The coil spring can be placed opposite to each other by using the tension of the coil spring provided on the lower valve pin, and the coil spring is provided with an upper ring-shaped stopper screwed with a screw groove provided on the inner wall of the recessed portion, and a lower part. Because it is locked between the flange of the lower valve pin that is regulated between the flange of the insertion tube, the upper mold including the manifold and the lower mold including the valve body can be easily separated. As a result, the mold can be disassembled, repaired and cleaned in a state where the upper valve pin and the lower valve pin are separately separated.

  In addition, the upper valve pin is merely linked to the reciprocating drive as a push rod that does not require much accuracy, and it is only necessary to maintain the high accuracy of the lower valve pin that opens and closes the gate, thereby reducing the overall cost.

  Furthermore, since the lower valve pin is built in the valve body, there is an advantage that a custom-made pin is eliminated.

Furthermore, since the digging of the upper valve pin can be standardized and the closed position of the lower valve pin is regulated by the valve body body, the requirement for the digging accuracy of the piston of the upper valve pin is low.
And in the size of the molded product or multi-piece molding, etc., the valve valve is divided into upper valve pin and lower valve pin even for many kinds of valve pins, so the expensive lower valve pin is large, medium, small etc. Prepared as a standardized qualitative product, and the upper valve pin of different types, lengths, etc., can be provided at a low cost each time, providing an efficient and inexpensive molding machine mold. .

  Further, when the mold is divided, it is not necessary to raise the temperature and pull out the lower valve pin. Therefore, the division can be easily performed even when the temperature cannot be raised due to disconnection of the body heater.

1 shows one embodiment of a split type valve pin according to the present invention, in which (a) is a side view of a piston inoperative state, and (b) is a side view of a piston in activated state Schematic sectional view of a mold part showing an embodiment of a split valve pin gate system according to the present invention 1A and 1B show a connection configuration of an upper valve pin and a lower valve pin of a split valve pin according to the present invention, in which FIG. 1A is an enlarged sectional view of a coupling mechanism in a gate open state, and FIG. Fig. (C) is an enlarged cross-sectional view when the upper valve pin and the lower valve pin are not in contact

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  1 is a mold that shows a schematic cross-sectional view of the main part of a thermoplastic synthetic resin device, 2 is a mounting plate that is in contact with a nozzle of an injection molding machine and opens an injection port through which a molten resin material is injected. A piston provided on the head of the upper valve pin a is disposed in a cylinder 4 provided on the mounting plate 2 so as to be reciprocally driven and driven by a fluid such as air pressure or hydraulic pressure. 5 is a manifold through which the upper valve pin a is inserted, and 6 is arranged on the same straight line as the upper valve pin a, and is separated from the upper valve pin a and through a separate lower valve pin b. A valve body abutting on the manifold 5 is shown, and the molten resin flow hole 7 communicating with the manifold 5 and the insertion hole 8 of the valve body 6 merge in the middle to form a single molten resin flow hole 9. Forming. A gate 10 communicates with a cavity 11 formed below the molten resin flow hole 9. A pin portion b1 at the lower end of the lower valve pin b can open and close the gate 10 through the molten resin flow hole 9.

  c is a connecting mechanism for connecting the upper valve pin a and the lower valve pin b, and the lower end a1 of the upper valve pin a inserted through the manifold 5 and the head b2 of the lower valve pin b are in contact with each other. Yes.

  12 is a recessed portion corresponding to a guide portion recessed in the opening of the insertion hole 8 of the valve body 6 in which the flange 13 formed on the head b2 of the lower valve pin b can reciprocate, and 14 and 15 are recessed portions. The upper and lower stoppers disposed above and below the screw 12 are screwed into a screw groove 16 provided on the inner periphery of the recessed portion 12 to be screwed and fixed while maintaining a desired interval h. Reference numeral 17 denotes a coil spring interposed between the flange portion 8b of the insertion tube 8a that forms the insertion hole 8 that supports the lower stopper 15 and the flange portion 13 provided on the head portion b2 of the lower valve pin b. Reference numeral 18 denotes a set screw for assembling the mold 1, 19 denotes a spacer block, and 20 denotes a fluid through hole formed in the mold 1. The valve body 6 may be configured to keep the molten resin material warm by incorporating a heater inside the outer periphery as necessary.

  Further, as shown in FIG. 3 (c), even if the head b2 of the lower valve pin b and the lower end a1 of the upper valve pin a may be separated with a gap g, there is no problem as long as the structure and operation are small. .

  In particular, the upper valve pin a that penetrates the manifold 5 functions as a push rod, and the length can be made with general tolerances, so that it can be used for simple processing of commercially available pins, and the digging of the cylinder 4 is also adjusted with the upper valve pin a. Because it can, it can be processed with a fixed digging size.

  The operation will be described based on the above configuration.

  During the injection molding operation, the raw material molten resin is injected into the mold 1 from the injection port of the mounting plate 2. The piston 3 in the cylinder 4 provided on the mounting plate 2 in conjunction with this injection molding operation is It moves by receiving fluid pressure such as oil pressure or air pressure, and reciprocates.

  By this reciprocating drive operation, the upper valve pin a slides back and forth in the mold 1 as well. Since the lower end a1 of the upper valve pin a is connected to the head b2 of the lower valve pin b via the connecting mechanism c, the upper valve pin a is driven to reciprocate similarly.

  Specifically, as shown in FIGS. 3A and 3B, for the downward driving operation of the upper valve pin a, the lower end a1 of the upper valve pin a connects the head b2 of the lower valve pin b with the coil spring 17. The lower valve pin b descends through the insertion hole 8 of the valve body 6, and the pin portion b 1 at the lower end of the lower valve pin b closes the gate 10 and flows the molten resin into the cavity 11. The injection resin molding process in the cavity 11 can be accurately performed.

  On the other hand, if the upper valve pin a is moved back by driving the piston 3 upward, the contact pressure applied to the head of the lower valve pin b disappears. Therefore, the repulsion of the coil spring 17 that has been compressed and accumulated the repulsive force. Due to the force, the lower valve pin b rises, and as a result, the pin portion b1 at the lower end of the lower valve pin b is separated from the gate 10 and the gate 10 can be opened.

  The connecting mechanism c that connects the upper valve pin a and the lower valve pin b is formed at the head of the lower valve pin b at the recessed portion 12 that expands in the opening of the insertion hole 8 of the valve body 6 provided in contact with the lower portion of the manifold 5. The portion b2 and the lower end a1 of the upper valve pin a can be placed opposite each other using the tension of the coil spring 17 provided on the lower valve pin b, and the coil spring 17 is screwed on the inner wall of the recessed portion 12. Since the upper ring-shaped stopper 14 screwed into the groove 16 and the flange portion 13 of the lower valve pin b that is regulated between the flange portion 8b of the lower insertion tube 8a are locked, The upper mold 1 including 5 and the lower mold 1 including the valve body 6 can be easily separated.

  As a result, the disassembly / repair / cleaning operation of the mold 1 in a state where the upper valve pin a and the lower valve pin b are separated from each other can be performed very efficiently.

  Furthermore, in the case of the size of a molded product or multi-cavity molding, for example, many types of valve pins are divided into an upper valve pin a and a lower valve pin b, which requires high-precision processing and is expensive. The lower valve pin is prepared as a qualitative product standardized in large, medium, small, etc., and the upper valve pin of different types and lengths is commercialized and offered at a low price each time. The mold can be provided efficiently and inexpensively.

  Similarly, the upper valve pin a can be standardized and the lower valve pin b can be commercialized each time.

  In the above-described embodiment, the reciprocating drive configuration of the upper valve pin a has been described specifically for the piston 3 and cylinder configuration, but can be similarly implemented using a cam drive system different from this configuration (not shown). .

DESCRIPTION OF SYMBOLS 1 Mold 2 Mounting plate 3 Piston 4 Cylinder 5 Manifold 6 Valve body 7 Flow hole 8 Insertion hole 8a Insertion tube 8b Gutter part 9 Molten resin flow hole 10 Gate 11 Cavity 12 Recessed part 13 Gutter part 14, 15 Upper and lower stoppers 16 Screws Groove 17 Coil spring 18 Set screw 19 Spacer block 20 Through hole a Upper valve pin b Lower valve pin c Connection mechanism h Interval g Gap b1 Lower end of lower valve pin b (lower end of lower valve pin b)
b2 Head of lower valve pin b a1 Lower end of upper valve pin a

Claims (1)

A valve pin used for an injection molding operation, wherein an upper valve pin and a lower valve pin that are reciprocally driven are formed separately and arranged in a straight line, and the lower end of the upper valve pin inserted through the manifold is paired with the head of the lower valve pin. The coil spring is interposed between the head portion of the lower valve pin and the flange portion of the insertion tube so as to be able to move back and forth through the coupling mechanism, and the coupling mechanism is recessed in the valve body. The upper and lower ring-shaped stoppers that are screwed into the screw grooves provided on the inner periphery of the recessed portion are disposed at intervals so that the flange formed on the head of the lower valve pin can slide only between the stoppers. split valve pin, characterized by comprising by.

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