JPH0742677Y2 - Sandwich molding nozzle - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle used for so-called sandwich molding in which the cross section of a molded product is composed of a core layer and a skin layer in the field of plastic molding.

[0002]

2. Description of the Related Art Conventionally, as a sandwich molding nozzle, there are nozzles disclosed in, for example, Japanese Examined Patent Publication No. 1-24052 or Japanese Utility Model Laid-Open No. 63-161811. An example of a conventional sandwich molding nozzle will be described with reference to FIG.

A hollow outer nozzle 1 has a first resin injection hole 4 communicating with a first injection device (not shown) and a second resin injection hole 5 communicating with a second injection device (not shown). At the same time, the tip (the left end in the figure) is provided with an injection port 1a for injecting resin into a mold (not shown). In addition, 16 is a connection part with a machine frame (not shown).

Reference numeral 2 denotes a hollow inner nozzle, which is slidably inserted in the inner diameter surface of the outer nozzle 1 in the right and left arrow directions through a driving device (not shown) provided on the right side of the drawing, and has a tip (see FIG. Has a resin discharge port 2a at the left end) and a void 6 is formed between the outer diameter surface near the tip and the inner diameter surface of the outer nozzle 1, and the void 6 and the first resin injection hole 4 are formed. And the resin passage 8 are connected to each other. Figure 2
Shows the state where the inner nozzle 2 slides to the left and the tip contacts the inner surface of the end portion of the outer nozzle 1.

A needle 3 is slidably fitted in the inner diameter surface of the inner nozzle 2 to form a space 7 between the outer diameter surface near the tip and the inner diameter surface of the inner nozzle 2. A resin passage 9 communicating with the void portion 7 is provided, and the void portion 7 and the second resin injection hole 5 are communicated with each other via a resin communicating hole 10 provided in the diameter direction of the inner nozzle 2. FIG. 2 shows a state in which the needle 3 slides to the left and the tip comes into contact with the inner surface of the end portion of the inner nozzle 2.

In molding plastic, after the tip of the outer nozzle 1 is brought into contact with the injection port of the mold, the first injection device and the second injection device simultaneously or simultaneously switch (in this case, the inner nozzle 2 And the needle 3 are appropriately slid in the left and right arrow directions), and the resin is injected into the cavity of the mold.

[0007]

The conventional sandwich molding nozzle described above has an inner diameter surface of the outer nozzle 1 and an outer diameter of the inner nozzle 2 so that the inner nozzle 2 and the needle 3 slide smoothly during molding. Between the faces,
Also, an appropriate sliding interval is required between the inner diameter surface of the inner nozzle 2 and the outer diameter surface of the needle 3.

Because of this sliding distance, when the molten resin is injected by the first and second injection devices at a constant pressure, the resin leaks from the sliding distance to the outside on the right side of FIG. (Leakage of resin) occurs and gradually solidifies to form large solidified portions 20 and 21.

When the solidified portions 20 and 21 are formed, the smooth sliding of the inner nozzle 2 and the needle 3 is hindered, and the solidified portions 20 and 2 formed in a narrow place are formed.
It is extremely difficult to remove 1 and requires a lot of man-hours. The present invention solves the above problems in the conventional nozzle, provides a sandwich molding nozzle in which resin leakage to the outside in the sliding direction of the inner nozzle 2 and the needle 3 is prevented, and the leaked resin is easily removed. That is the purpose.

[0010]

The present invention has been made as a result of various studies in order to achieve the above object, and has first and second resin injection holes and a resin injection port at the tip. And a hollow outer nozzle, which is slidably fitted into the inner diameter surface of the outer nozzle, has a resin discharge port at the tip, and is provided between the outer diameter surface near the tip and the inner diameter surface of the outer nozzle. A hollow inner nozzle having a void formed therein and the first resin injection hole communicating with the void by a resin passage, and a hollow inner nozzle slidably fitted into the inner diameter surface of the inner nozzle, A void portion is formed between an outer diameter surface and an inner diameter surface of the inner nozzle, and a resin passage communicating with the void portion is provided, and the void portion is provided through a resin communication hole provided in a diameter direction of the inner nozzle. And the second resin injection In a sandwich molding nozzle including a needle communicating with the outer nozzle, the outer nozzle of the outer nozzle is provided at a position between the position of the first or second resin injection hole and the drive source side end of the outer nozzle. A peripheral groove is provided on the inner diameter surface and communicates with a resin draining hole that is open downward, and a peripheral groove is provided on the inner diameter surface of the inner nozzle. It is characterized in that it is communicated with a resin drain hole which is provided on the outer nozzle and opens downwardly outside through the communication hole.

[0011]

In the nozzle having the same structure and function as the conventional one, since the peripheral groove and the resin drain hole are provided at the above-mentioned positions so as to communicate with each other, the resin which tends to leak from the sliding gap between the outer nozzle and the inner nozzle. After being temporarily stored in a peripheral groove provided on the inner diameter surface of the outer nozzle, the resin flows downward through a downward resin drain hole communicating with the peripheral groove and is discharged to the outside.

The resin which leaks out from the sliding gap between the inner nozzle and the needle is discharged from the circumferential groove provided on the inner diameter surface of the inner nozzle in the same manner as described above, in this case, through the communication hole to the resin removal hole. Is discharged to the outside.

Therefore, the molten resin does not leak from the end portion on the drive source side and solidify to prevent the sliding of the inner nozzle and the needle. Also, since the resin discharged from the resin drain hole solidifies and hangs down in the shape of a rod or strip,
It can be removed very easily and in a short time.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In the description, the same members and the like as those in the conventional example (FIG. 2) are designated by the same reference numerals, and the duplicated description of the structure, the action and the like will be omitted. In FIG. 1, 11 is an outer nozzle 1.
The outer groove of the outer nozzle 1
Is communicated with the resin drain hole 12 that is provided at the bottom and opens downwardly to the outside. The circumferential groove 11 and the resin drain hole 12 are provided between the first and second resin injection holes 4 and 5 and the drive source side of the outer nozzle 1 (the end portion 1c on the right side in the drawing). When the positions of the first and second resin injection holes 4 and 5 in the left-right direction are different, they are provided between the resin injection holes 4 and 5 which are closer to the end 1c.

Reference numeral 13 is a peripheral groove provided on the inner diameter surface of the inner nozzle 2, and is provided on the outer nozzle 1 through a communication hole 14 also provided in the diameter direction of the inner nozzle 2 so as to communicate with the peripheral groove 13. And communicates with a resin drain hole 15 that opens downward to the outside. And these circumferential grooves 1
3, the communication hole 14, and the resin drain hole 15 are provided between the first and second resin injection holes 4 and 5 and the end portion 1c of the outer nozzle 1 as described above. In addition, 16 is an outer nozzle 1
Although it is an auxiliary peripheral groove provided on the inner diameter surface of, it may be omitted.

Due to the above structure, when the molten resin is injected during sandwich molding, the molten resin will be injected into the outer nozzle 1.
Let's leak from the sliding gap between the inner nozzle 2 and the inner nozzle 2 and the sliding gap between the inner nozzle 2 and the needle toward the end 1c of the outer nozzle 1 and the end 2c of the inner nozzle 2 (rightward in the figure). However, the circumferential groove 1
Since there are 1 and 13, they are collected in this.

The resin accumulated in the circumferential groove 11 flows down through the resin drain hole 12 communicating with the circumferential groove 11 and is discharged. Further, the resin accumulated in the circumferential groove 13 is
Through the communication hole 14 communicating with the resin discharge hole 15 and discharged downward. Therefore, it does not leak from the end portion 1c of the outer nozzle 1 and the end portion 2c of the inner nozzle 2 and solidify to prevent the inner nozzle 2 and the needle 3 from sliding.

It should be noted that the resin discharged downward is dropped and directly recovered, or when solidified, it hangs down in the form of a rod or a strip, so it can be removed very easily and in a short time by breaking it off. it can.

[0019]

As described above, according to the present invention, the resin leaking from the sliding gap does not solidify at the sliding portion and hinders the sliding of the inner nozzle and the needle, and the discharged resin is Since it hangs downward to the outside and solidifies, it can be removed easily and in a short time, and the number of working steps can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an example of a conventional sandwich molding nozzle.

[Explanation of symbols]

 1 Outer Nozzle 1c End 2 Inner Nozzle 2c End 3 Needle 4 First Resin Injection Hole 5 Second Resin Injection Hole 6 Void 7 Void 11 Circumferential Groove 12 Resin Removal Hole 13 Circumferential Groove 14 Communication Hole 15 Resin Removal Hole

Claims (1)

[Scope of utility model registration request] 1. A hollow outer nozzle having first and second resin injection holes, and a resin injection port at the tip, and a hollow outer nozzle slidably inserted into the inner diameter surface of the outer nozzle, A resin discharge port is provided, and a void is formed between the outer diameter surface near the tip and the inner diameter surface of the outer nozzle, and the void and the first resin injection hole are connected by a resin passage. And a hollow inner nozzle, which is slidably fitted into the inner diameter surface of the inner nozzle to form a gap between the outer diameter surface near the tip and the inner diameter surface of the inner nozzle, and the gap portion. And a needle for communicating the void and the second resin injection hole via a resin communication hole provided in a diameter direction of the inner nozzle. In the first Alternatively, a peripheral groove is provided on the inner diameter surface of the outer nozzle at a position between the position of the second resin injection hole and the end portion on the drive source side of the outer nozzle so that the outer nozzle communicates with the resin drain hole that opens downward. At the same time, a peripheral groove is provided on the inner diameter surface of the inner nozzle, and a diametrical communication hole communicating with the peripheral groove is provided, and a resin draining hole provided outside the outer nozzle provided in the outer nozzle through the communication hole is provided. Nozzle for sandwich molding characterized by being able to communicate with the hole.