JPS6315893B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection molding machine comprising upper and lower molds and a pressure cylinder having a nozzle portion that comes into contact with and separates from a sprue bush of the upper mold. The upper end is formed into a convex spherical surface, and the tip of the nozzle part is formed into a concave spherical surface that matches the convex spherical surface, and further, a cul removal member that rubs against the convex spherical surface of the sprue bush is attached to the upper metal. This relates to an injection molding machine that is installed in a mold so that it can move horizontally into and out of the mold.

Conventionally, there are various types of injection molding machines for molding synthetic resins, but the one shown in FIG. 1 is the most common.

That is, 1 is an upper mold, and 2 is a lower mold, which are attached to an upper mold plate 3 and a lower mold plate 4, respectively. A sprue bush 5 is installed in the upper mold 1, and has a sprue passage 6 bored therein and communicates with a mold engraving space 7. The upper end surface of the sprue bush 5 is formed into a concave spherical surface 8. On the other hand, 9 is a pressure cylinder,
A nozzle part 10 is provided at the tip. The nozzle part 1
0 is provided with a nozzle hole 11, and the tip of the nozzle portion 10 is connected to the sprue bush 5.
It is formed into a convex spherical surface 12 that matches the concave spherical surface 8 of. In addition, 13 is a screw in the pressure-resistant cylinder 9, and 14 is a heater provided around the upper and lower molds 1 and 2.

As mentioned above, in conventional injection molding machines,
The upper end of the sprue bush 5 is formed into a concave spherical surface 8,
A configuration is adopted in which the tips of the nozzle parts 10 are formed into convex spherical surfaces 12 so that they come into spherical contact with each other during joining. One reason for this is that a centripetal force is applied when the nozzle parts 10 are brought into contact with the sprue bush 5. This is to bias the nozzle portion 10 and align the nozzle hole 11 with the sprue passage 6. The other problem is the difficulty in manufacturing convex spherical surfaces and concave spherical surfaces.Generally speaking, concave spherical surfaces, which are relatively easy to manufacture, are used in molds that have a larger number of nozzles, and molds that are relatively easier to manufacture than nozzles. This is because it was thought to be advantageous to form convex spherical surfaces, which are difficult to manufacture, on the respective parts.

Incidentally, in recent years, with the spread of various types of thermosetting resins, a transfer method in which the mold is moved to a work site for the next process while the mold is in a clamped state has been increasingly adopted.

In other words, in many cases with thermosetting resins, the mold is heated to harden the resin in the engraving space, but this curing reaction takes a relatively long time, and it takes a long time for the resin to harden. Leaving injection molding on standby significantly reduces work efficiency. Therefore, work efficiency is improved by moving the mold and releasing the pressure cylinder for the next injection process while the mold is in a clamped state and the resin in the mold engraving space has not yet hardened. things are being done. For this purpose, it is necessary to remove the nozzle from the mold immediately after injection molding.

On the other hand, when molding thermosetting resin, the mold is heated, so heat is transferred from the mold to the nozzle, hardening the resin in the nozzle, and making the nozzle more likely to become clogged. It is necessary to separate the nozzle from the mold.

As mentioned above, in thermosetting resin molding, the nozzle is removed from the mold immediately after the injection process due to the above two reasons. As the resin in the molding space 7 hardens, the sprue bush 5
The excess resin overflows through the sprue passage 6 and is deposited on the concave spherical surface 8, forming a so-called cull 15. In the next step, the cull 15 is crushed by the convex spherical surface 12 at the tip of the nozzle, and accumulates and grows from shot to shot, until the nozzle part 10 and the sprue bush 5 cannot be connected, making molding impossible. There was a drawback.

Since the cull is formed on the concave spherical surface 8, it cannot be removed automatically, and must be removed manually each time, which is cumbersome and reduces work efficiency. There was a problem.

In view of the problems such as the occurrence of cull due to the structural limitations of the injection molding machine based on the above-mentioned prior art, an object of the present invention is to form the joint between the sprue bush and the nozzle part so that the sprue bush side has a convex spherical surface. By forming the nozzle side into a concave spherical surface and incorporating the cul removal member into the mold so that it can freely appear and retract, the above-mentioned drawbacks and difficulties are eliminated, and the cul formed on the sprue bushing is minimized. It is an object of the present invention to provide an excellent injection molding machine that can remove dust efficiently.

The structure of the present invention in accordance with the above object is such that when the nozzle is removed from the mold after the injection process, the overflow of the resin due to hardening of the resin between the mold engraving spaces is guided onto the convex spherical surface of the upper surface of the sprue bush, and the part The basic gist is that the cull generated in the step can be removed below the convex spherical surface by the concave spherical surface formed on the nozzle part when the nozzle comes into contact in the next step, and further,
The gist of the present invention is that the cul still deposited on the convex spherical surface can be removed by a removing member.

Next, an embodiment of the present invention will be described below based on the drawings from FIG. 3 onwards.

In the embodiment shown in FIG. 3, the upper surface of the sprue bush 5 has a convex spherical surface 1
6. On the other hand, the tip of the nozzle portion 10 of the pressure cylinder 9 has a concave spherical surface 17 that matches the convex spherical surface 16.
is formed.

Furthermore, in the embodiment of the second invention related to this invention shown in FIG. 4 and below, a cull removing member 18 is incorporated into the upper mold 1 so as to be horizontally retractable. The cull removing member 18 is formed with a groove 19 having an arcuate cross section at least at its tip, and the groove 19 has a cross-sectional shape that matches the convex spherical surface 16 at the upper end of the sprue bush 5. The rear portion 20 of the cul removal member 18 is connected to a suitable driving source, such as an air cylinder, and is capable of moving in and out of the convex spherical surface 16 of the sprue bush 5.

Note that the other components are the same as those indicated by the same reference numerals in FIGS. 1 and 2.

In the above structure, when performing injection molding work, the pressure cylinder 9 is lowered to bring the nozzle portion 10 into contact with the sprue bush 5, as shown in FIG. At this time, the convex spherical surface 16 of the sprue bush 5 and the concave spherical surface 17 of the nozzle portion 10 come into spherical contact and are combined.
Then, when the nozzle part 10 is separated from the sprue bush 5 after injection molding, when the resin in the mold engraving space 7 hardens, a part of the resin overflows to the convex spherical surface 16 through the sprue passage 6, and the convex A cull is formed on the spherical surface 16.

However, when the nozzle part 10 comes into contact with the sprue bush 5 in the next step, the cull formed on the convex spherical surface 16 by the concave spherical surface 17 of the nozzle part 10 is pushed downward, and the cull formed on the convex spherical surface 16 is pushed downward. be excluded from

On the other hand, in the embodiment shown in FIG. 4 and subsequent figures, when the cull 15 that cannot be removed even by the above-mentioned action is deposited on the convex spherical surface 16 of the sprue bush 5, the cull removing member 18 is appropriately activated as a drive source. Then, it is moved forward, and as shown in FIG. 6, the arcuate groove 19 is adapted to the convex spherical surface 16, and the surface of the convex spherical surface 16 is rubbed to remove the cull 15.

After the cul removal work is completed, the cul removal member 18 is retreated from the convex spherical surface 16 in preparation for the next molding process.

It should be noted that the cul removal member 18 removes the convex spherical surface 1 with one rubbing.
Of course, if Cull 15 cannot be completely removed from 6, it can be made to appear and appear several times.

As described above, according to the present invention, at the joint between the sprue bush and the nozzle part, a convex spherical surface is formed at the top of the sprue bush and a concave spherical surface is formed at the tip of the nozzle part. The generated overflow of resin to the upper part of the sprue bushing is guided onto the convex spherical surface, and cull is generated on the convex spherical surface, so that when the nozzle part descends into contact in the next process, the spherical surface of the nozzle part There is an excellent effect in that the cull on the convex spherical surface can be pushed downward and automatically removed from the convex spherical surface. Therefore, no cull remains on the contact surface between the nozzle portion and the sprue bushing, and the molding operation is not interrupted, resulting in a marked improvement in work efficiency.

Also, according to the second invention linked to this invention,
Since the structure is such that the cul removing member is built into the mold so that it can freely appear and retract, if cul is still deposited on the convex spherical surface due to the above action, the cul removing member is moved forward and the cul removing member is removed. The groove having an arcuate cross section is engaged with the convex spherical surface, and the convex spherical surface is rubbed against the surface, thereby providing an excellent effect in that accumulated cull can be easily peeled off.

Therefore, the convex spherical surface of the sprue bushing is always kept in a state where no cull is deposited, and the molding operation can be performed extremely smoothly.

Incidentally, since the spherical contact between the sprue bush and the nozzle portion remains the same as in the prior art, there is no problem in automatic alignment of the two by the centripetal force at the time of contact.

[Brief explanation of the drawing]

Fig. 1 and Fig. 2 show a conventional injection molding machine, Fig. 1 is a sectional view during injection molding, Fig. 2 is a sectional view during resin curing, and Fig. 3 is an embodiment of the present invention. 4 is a sectional view of an embodiment of the second invention related to this invention, and FIG. 5 is a sectional view taken along A-A in FIG. 4.
The cross-sectional view, FIG. 6, is an operational cross-sectional view of the embodiment of the second invention. DESCRIPTION OF SYMBOLS 1...Upper mold, 2...Lower mold, 5...Sprue bush, 6...Sprue passage, 7...Die engraving space, 9...Pressure cylinder, 10...Nozzle section, 11...
Nozzle hole, 14...Heater, 15...Cull, 1
6...Convex spherical surface, 17...Concave spherical surface, 18...Cull removal member, 19...Circular groove.

Claims (1)

[Claims] 1. An upper mold 1, a lower mold 2, a sprue bush 5 mounted on the upper mold, and a pressure cylinder 9 having a nozzle part 10 that comes into contact with and separates from the sprue bush.
An injection molding machine comprising: a joint portion of the sprue bush with the nozzle portion formed into a convex spherical surface 16; and a tip of the nozzle portion formed into a concave spherical surface 17 compatible with the convex spherical surface. injection molding machine. 2. An upper mold 1, a lower mold 2, a sprue bush 5 installed on the upper mold, and a pressure cylinder 9 having a nozzle part 10 that comes into contact with and separates from the sprue bush.
In the injection molding machine, the joint part of the sprue bush with the nozzle part is formed into a convex spherical surface 16, the tip of the nozzle part is formed into a concave spherical surface 17 that matches the convex spherical surface, and An injection molding machine characterized in that a cul removal member 18 which is movable in the horizontal direction and which rubs against the convex spherical surface of the sprue bush is incorporated in the mold.