JP3035564U - Valve gate device for injection molding - Google Patents

Abstract

(57) An object of the present invention is to provide a valve gate device for injection molding, which is accurately processed by a single member without dividing a part and is suitable for inexpensive mass production. SOLUTION: A valve pin hole 3 is bored in an axial direction of a single-body bullet type probe main body 1 having a heating means, a valve pin 4 is reciprocally inserted, and a valve gate 6 leading to a cavity is opened and closed. A molten resin flow hole 7 is provided in the probe main body 1 at a location separated from the valve pin hole 3.
A valve gate apparatus for injection molding, characterized in that the molten resin flow hole 7 and the valve pin hole 3 are communicated with each other by forming an inclined hole 8 from the opening end of the valve pin hole 3.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to an injection molding valve gate device in which a valve pin working passage and a molten resin flow hole can be machined by a single member without dividing the parts.

[0002]

[Prior art]

 This type of valve gate device is provided with a molten resin flow hole separately from the valve pin operating passage, and both of them are formed so as to join and communicate with each other at the lower part of the valve pin hole through which the valve pin reciprocates.

[0003]

[Problems to be solved by the device]

 Therefore, it is inevitable that the upper and lower members are composed of the upper and lower members with the junction of the molten resin flowing hole located under the valve pin hole and the valve pin hole as a boundary, and the parts must be divided.

In other words, there is a disadvantage that the through hole and the valve pin hole must be processed by separate members. Therefore, it is necessary to combine these two members in a matched manner, so it is necessary to process parts that require dimensional accuracy, and if the processing accuracy is poor, the molten resin will leak from the joint between the two members. There was an inconvenience.

An object of the present invention is to provide a valve gate device for injection molding, which can be accurately processed by a single member without dividing the parts and is suitable for mass production at low cost.

[0006]

[Means for Solving the Problems]

 This invention was made with attention to the above points, and solved the above problems by having the following configuration.

(1) A valve pin hole is bored in the axial direction of a single-body bullet type probe main body provided with a heating means, and the valve pin is reciprocally inserted therethrough to open and close a valve gate communicating with the cavity, and at the same time, the valve pin is opened. A valve for injection molding characterized in that a molten resin flow hole is provided in the probe main body separated from the hole, and the molten resin flow hole is communicated with the valve pin hole by forming an inclined hole from the opening end of the valve pin hole. Gate device.

(2) The heating means has a body heater provided on the outer peripheral cylinder of the probe main body and a tip heater provided on the outer peripheral tip end, and is fitted onto the outer periphery of the probe main body by a shell-shaped hollow cover. The injection molding valve gate apparatus according to (1) above.

(3) The heating means is characterized in that the body heater is provided only on the outer peripheral cylinder portion of the probe main body, and the heating means is fitted on the outer periphery of the probe main body by a shell-shaped hollow cover (1 ) A valve gate device for injection molding according to the above.

(4) The injection molding according to (2) or (3), characterized in that the conical tip of the hollow cover is provided with a tip locking portion that determines a locking position with the fixed mold. Valve gating device.

[0011]

[Action]

 For the valve pin facing the opening end of the valve pin hole installed vertically in the probe body, part of the lower part of the valve pin hole is shared, and it is connected from the opening end of this valve pin hole to the molten resin flow hole through the inclined hole. The molten resin is surely and reliably injected into the cavity through the molten resin through hole, the inclined hole, the gate land of the mold, and the gate each time the molding operation is performed. At the same time, the valve pin descends in the valve pin hole to close the valve gate and perform mold clamping. Then, when the solidification of the resin in the cavity is completed, the valve pin returns to the initial position by the backward stroke operation, the mold opening is performed, and the preparation for the next injection operation is started.

Since the molten resin flow hole of the probe body shares the opening end of the inclined hole of the molten resin flow hole with the opening end of the valve pin hole, all the holes are made of a single constituent member. It can be processed reliably and easily, and since it is a single member, there are no joints to be joined, so there is no inconvenience of combination accuracy or leakage of molten resin.

[0013]

[Embodiment of the invention]

 An embodiment of the present invention will be described below.

First, a basic form will be described with reference to FIGS. 1 to 3.

Reference numeral 1 is a shell-shaped probe main body in which the tip 2 is formed in a conical shape, and is provided with a heater H on the outer circumference. Reference numeral 3 is a valve pin hole that penetrates along the central axis of the probe body 1, and a valve pin 4 is reciprocally inserted therethrough. The valve pin 4 passes through the valve pin hole 3 from the state shown in FIGS. 1 and 2, and advances from the opening end 3a thereof to the valve gate 6 at the position shown in FIG. 3 through the gate land 5 of the mold. It retreats and opens and closes the gate 6. Reference numeral 7 denotes a molten resin flow hole which is vertically passed through the probe main body 1 at a position apart from the valve pin hole 3, and 8 denotes an inclined hole which reaches the molten resin flow hole 7 from the opening end 3a of the valve pin hole 3. It is preferable that the tilt angle is as gentle as possible.

Next, another embodiment will be described with reference to FIGS. 4 to 6.

As shown in the figure, the probe body 1 is provided with a coiled body heater H ₁ located at a cylindrical portion on the outer periphery thereof, and mainly heats and holds the molten resin in the molten resin flow hole 7. It is intended for heating, and a step portion 1a is formed at a conical portion at the tip of the outer circumference, and the step portion 1a can locally heat the vicinity of the inclined hole 8 and the opening of the valve pin hole 3. A coil-shaped chip heater H ₂ is wound, and these heaters H ₁ and H ₂ are fitted and assembled by a shell-shaped hollow cover 9.

In each figure, 10 is a manifold to which the bases of a large number of probe bodies 1 are fixed, and 11 is a tip guide portion 12 provided on the peripheral surface of the conical tip portion 2 of the probe body 1 for engaging the probe body 1. 1 shows a fixed mold of an injection molding die which can be held and held, and a valve gate 6 including the gate land 5 is bored in the fixed mold 11. Reference numeral 13 indicates a temperature sensor.

The operation will be described based on the above configuration.

The molten resin injected from the manifold 9 to each mold passes through one molten resin flow hole 7 of each probe body 1 and an inclined hole 8 near the tip, and the open end 3 a of the valve pin hole 3 1. After reaching the gate land 5 of the mold through the above, it is further injected into the cavity formed by the valve gate 6 between the fixed mold 11 and a movable mold (not shown).

The molten resin has no inconvenience that the flow path thereof is dispersed in the probe main body 1 due to an extremely bent portion that obstructs the flow or shunting, and the course is changed by the inclined hole 8. Since it is gradual, it progresses with almost straight flow operation, and therefore no weld or distortion occurs.

Simultaneously with the completion of the injection operation, the valve pin 4 descends, the valve gate 6 is closed, and thereafter, the mold clamping operation is started (see FIGS. 3 and 6).

After the mold clamping operation for a predetermined time, the movable mold (not shown) moves backward to perform the mold opening operation to take out the molded product in the cavity, and then move the movable mold to the current position again to perform the closing mold operation. The valve pin 4 is returned to the state shown in FIGS. 1, 2 or 4 and 5 during the operation.

Although one injection molding operation is completed as described above, continuous molding can be performed by repeating the same operation.

According to the above operation, the molten resin does not flow through the independent molten resin flow hole 7 which is completely different from the valve pin 4 and flows through the inclined hole 8 from the opening end 3 a of the common valve pin hole 3. It goes through the gate land 5 to the valve gate 6 and is injected smoothly and smoothly into the cavity from this gate 6 to prevent the strength of the molded product from decreasing, and also to prevent welds and distortions caused by changes in the flow of the molten resin. It is possible to mold extremely high quality molded products with good yield.

The tip heater H ₂ provided at the tip of the probe body 1 is actuated immediately before the injection operation to reheat and melt the resin in the inclined hole 8 portion that has been cooled to a semi-solidified or semi-cured state. The operation can be performed smoothly and efficiently. If a high-density coil heater is used as the tip heater H _2, preheating to compensate for the temperature drop in the vicinity of the inclined hole 8 at the tip of the probe body 1 and temperature difference due to intermittent heating according to the molding cycle are used. Other controls with marks are also possible.

By the way, in the embodiment of the present invention, two types of body heater H ₁ and chip heater H ₂ are incorporated into the molten resin flowing through the molten resin flow hole 7, and the body heater H of the coil heater is incorporated. ₁ shows that the density of the coil winding amount varies in the longitudinal direction, and the portion where the temperature tends to decrease is set to a high winding amount to make the temperature distribution uniform and uniform. By controlling, it is possible to mold resin with a small temperature range.

Further, since the tip guide portion 12 provided on the conical tip portion 2 of the probe body 1 can be locked and fixed to the fixed die 10, the opening end 3 a of the valve pin hole 3 supporting the valve pin 4 and the valve gate 6 are connected. Easy centering.

Furthermore, since the inclined hole 8 can be formed from the opening end 3a of the valve pin hole 3 toward the molten resin flow hole 7 by an oblique direction, the probe main body 1 can be formed in order to form the inclined hole 8. It has the advantage that it does not need to be divided in two.

The heaters H ₁ and H ₂ to be wound around the outer circumference only have to be wound around the outer circumference of the probe body 1, and the winding means does not require complicated working steps.

Further, since the hollow cover 9 is merely for covering and protecting the outer periphery of the probe body 1, it does not require processing accuracy and can be easily manufactured at low cost.

[0032] In the embodiment described above, all of the body heaters H ₁ and Chippuhi over data H ₂ when is incorporated, is omitted chip heater H _2, MekuSo only body heater H ₁ There is also an embodiment (not shown).

[0033]

[Effect of the invention]

 According to this invention, since the flow path of the molten resin and the hole of the valve pin are formed by one component, the injection molding operation can be performed very accurately and efficiently without resin leakage, and the probe body can be processed. The molten resin flow hole, valve pin hole, and inclined hole that are formed need only be machined from a single shell-shaped probe body, and there is no need to accurately combine the two members as in the conventional case. Manufacturing can be done in a short time, mass productivity can be achieved, and it can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing a basic embodiment according to the present invention.

FIG. 2 is an explanatory cross-sectional view of the main part of the same as before the valve pin is actuated.

FIG. 3 is an explanatory cross-sectional view of the valve pin of FIG. 1 after operation.

FIG. 4 is a vertical cross sectional view showing another embodiment of the present invention.

FIG. 5 is an enlarged cross-sectional explanatory view before the operation of the valve pin of the same as above.

FIG. 6 is an enlarged cross-sectional explanatory view of the valve pin of FIG. 4 after the operation.

[Explanation of symbols]

1 Probe body 2 Tip part 3 Valve pin hole 4 Valve pin 5 Gate land 6 Valve gate 7 Molten resin flow hole 8 Inclined hole 9 Hollow cover 11 Fixed type 12 Tip guide part H heater H ₁ Body heater H ₂ Chip heater

Claims (4)

[Utility model registration claims] 1. A valve pin hole is bored in the axial direction of a single-body shell type probe main body having a heating means, and the valve pin is reciprocally inserted therethrough to open and close a valve gate communicating with the cavity, and the valve pin hole is also provided. A valve gate device for injection molding, characterized in that a molten resin flow hole is provided in a further separated probe main body, and the molten resin flow hole is communicated with an inclined hole from the opening end of the valve pin hole. . 2. The heating means comprises a body heater provided on the outer peripheral cylinder of the probe main body, a chip heater provided on the outer peripheral tip end, and a shell-shaped hollow cover fitted on the outer periphery of the probe main body. Claim 1 characterized by the above.
A valve gate device for injection molding as described. 3. The heating means comprises a body heater provided only on the outer peripheral cylinder portion of the probe body, and the heating means is fitted on the outer periphery of the probe body with a shell-shaped hollow cover. Valve molding machine for injection molding. 4. The injection molding according to claim 2 or 3, wherein a conical tip portion of the hollow cover is provided with a tip locking portion which determines a locking position with the fixed mold. Valve gate device.