JP3251054B2 - Injection molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved needle opening / closing nozzle for supplying a flowable resin through a gate to a cavity of an injection mold.

[0002]

2. Description of the Related Art In recent years, a needle opening / closing type nozzle as exemplified in FIGS. 7 and 8 has advantages such as a small resin pressure loss at the time of injection molding and a clean gate mark of a product. In recent years, it has been actively used to supply a flowable resin to a cavity of an injection mold. However, the needle 1 is, for example, as shown in FIG.
8, only the relatively upper portion is supported by the blade member 3, and in the example shown in FIG.
Of course, the flow rate of the resin flowing through the resin flow path 5 can be adjusted only by changing the diameter of the gate hole 7. Therefore, 1) radial displacement of the needle is likely to occur. When the position deviation of these radial direction is generated and the gate hole and the needle tip collides that one or both of the members is worn, As a result, burrs are generated in gate mark of the product.
This burr usually has a diameter difference between the tip of the needle and the gate hole of 0.
Occurs when the distance exceeds 01 mm. 2) Since the resin flows in the nozzle without receiving resistance, the heater for heating the nozzle to a flow state of the molding resin is arranged apart from the resin flow path. If the injection mold contains a plurality of products (cavities) and there is a difference in the size and weight of the products to be molded therein, it is not possible to balance the flow of the resin for each of them, thus reducing the gate diameter. A corresponding number of nozzles, of which type has been changed, must be used. There is such a problem.

[0003]

SUMMARY OF THE INVENTION It is possible to prevent radial displacement of a needle with respect to a gate hole in a needle opening / closing nozzle and to create various flow balances using a single needle opening / closing nozzle. It is to be.

[0004]

According to the present invention, a needle opening / closing nozzle is brought into contact with a gate hole of the fluidized resin supply passage, and the tip of the needle is positioned between its most advanced position and its most retracted position. A needle positioning and guiding member for positioning in the direction and guiding along the fluid resin supply path, a resin flow path is defined between the blade members of the needle positioning and guiding member, Is variable between the most advanced position and the most retracted position of the needle tip.

[0005]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; FIG. FIG. 1 shows a cross-section of a needle opening and closing nozzle 10 according to the present invention. The needle opening / closing nozzle 10 is generally inserted into a piston 12 and a resin supply path 14 for flowing resin supplied from a resin supply source (not shown) to a gate hole 20 as in the conventional product. Needle 16 connected to
And a gate bush 22 integrally formed with a gate hole 20 for injecting the resin into the cavity 18 of the injection molding die. Nozzle 24 is heated by a nozzle heater 1 26 to maintain the resin in a fluidized state.

Please refer to FIG. A positioning member 28 having a hole 26 having a diameter matching the gate hole 20 at a lower end thereof is incorporated in a tip portion of the nozzle 24. At least two blade members 30 are raised from the periphery of the hole 26 at a fixed distance in the circumferential direction at a fixed distance in a direction away from the hole 26 in the axial direction of the nozzle. Thereby, along each edge of the plurality of blade members 30 facing the nozzle center axis 32, the tip portion 34 of the needle 16 having a diameter that fits into the gate hole 20.
A guide passage 36 is created for

A portion of the positioning member 28 between the adjacent blade members 30 gradually expands from the periphery of the hole 26 to the outside in the radial direction, and ends at a portion matching the inner diameter of the resin supply passage 14. A conical surface 38 is formed. With such a configuration, an opening is provided between the blade member 30 and the conical surface 38, between the lower end of the distal end portion 34 of the needle and the circumferential portion of the hole 26 of the guide passage 36.
6 by adjusting the rearmost position of the end portion 3
A plurality of variable flow passages 40 are formed in which the area of the opening can be changed by moving 4. This variable flow passage 40 is eventually connected to the gate hole 2 through the hole 26.
Since it is connected to zero, by changing the opening area, it is possible to change the resin flow rate balance passing therethrough.

On the other hand, the needle 16 has its final retreat amount inside the nozzle 24 adjusted by a needle retreat amount adjusting bolt 42 (see FIG. 1) which can abut the rear end of the piston 12.
Further, the maximum advance amount is adjusted by a needle advance position adjustment washer 46 positioned at the lower end of the movement passage 44 of the piston 12. Therefore, the positioning member 28
The length of the vane member 30 is such that the guide passage 36 formed along the edge thereof can receive the movement of the tip portion 34 of the needle corresponding to the retreat amount and the most advanced position of the needle 16. Is set to

[0009]

The guide passage 36 of the positioning member 28 prevents collision of the tip portion 34 of the needle 16 with the gate hole 20, thereby preventing burrs at the gate mark of the product due to wear of one or both members. Is prevented from occurring. Further, since the plurality of variable flow passages 40 act as resistors against the resin flow in the nozzle, by adjusting the opening area to a necessary flow balance,
A plurality of molded articles having different shapes, sizes and weights (for example, V
HS cassette upper case, lower case, guard panel, etc.)
Can be formed in a single mold using only one type of nozzle.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a needle opening / closing type nozzle according to the present invention, showing a state where a needle tip is in a gate adjustment position.

FIG. 2 is a cross-sectional view of the needle opening / closing nozzle according to the present invention, showing a state where the tip of the needle is at a gate closed position.

FIG. 3 is a partially enlarged cross-sectional view of the needle opening / closing type nozzle according to the present invention, showing a state in which a tip portion of the needle is at a gate maximum open position.

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

FIG. 5 is a partially enlarged cross-sectional view of the needle opening / closing nozzle according to the present invention, showing a state where the tip end of the needle is in a gate adjustment open position.

FIG. 6 is a partially enlarged cross-sectional view of the needle opening / closing nozzle according to the present invention, showing a state where the tip of the needle is at a gate closed position.

FIG. 7 is a partially enlarged cross-sectional view of a tip portion of a conventional needle opening / closing nozzle.

FIG. 8 is a partially enlarged cross-sectional view of a tip portion of another embodiment of the conventional needle opening / closing nozzle.

[Explanation of symbols]

10: Needle open / close type nozzle 12: Piston 14: Resin supply path 16: Needle 18: Cavity 20: Gate hole 22: Gate bush 24: Nozzle 26: Hole 28: Positioning member 30: Blade member 32: Nozzle center axis 34: Needle 36: guide passage 38: conical surface 40: variable flow passage 42: needle retraction amount adjustment bolt 44: piston movement passage 126: nozzle heater

Claims (2)

(57) [Claims] 1. A needle opening / closing nozzle for supplying a flowable resin to an injection molding die through a gate, wherein the nozzle is configured to open and close a flowable resin supply path by reciprocating a needle in an axial direction. A gate hole of the fluid resin supply passage for positioning the needle tip portion in the radial direction between the most advanced position and the most retreat position of the needle openable nozzle and guiding the needle tip along the fluid resin supply passage. A needle positioning and guiding member is provided in contact with the needle positioning and guiding member ,
At least the most advanced position and the most retracted position of the needle tip
Between the needle tip and the peripheral surface of the needle tip.
At least two blade members, each adjacent blade
Connect between the fluid resin supply path and the gate hole between the root members
Needle opening and closing nozzles in which the resin flow paths for each are defined . 2. A blade member for a needle positioning and guiding member.
The area of each resin flow path defined between
By moving between the most advanced position and the most retracted position
The needle opening / closing nozzle according to claim 1, which changes.