JPH0435133Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an injection molding machine that performs molding by injecting raw resin into a mold.

(Prior art) Generally, in this type of injection molding machine, molding is performed by plasticizing raw resin in a heating cylinder and injecting the plasticized resin into a mold by advancing a screw. The raw resin is supplied from a hopper provided at the rear of the heating cylinder.

By the way, after molding is completed, when a different type of resin is used in the next cycle, the raw material resin remaining in the hopper is discharged for replacement, but conventionally this discharge was done by rotating the hopper and placing it on the side of the heating cylinder. I was going by letting it happen. That is, as shown in FIG. 3, the housing 3 is fixed to the rear part of the heating cylinder 2 into which the screw 1 is fitted so as to be rotatable and reciprocating.
A hopper turning device 4 is rotatably attached to the housing 3, a hopper 5 is fixed to the device 4, a raw material supply port 6 is formed in the device 4, the side wall of the heating cylinder 2, and the housing 3, and A shutter 7 for opening and closing the discharge port of the hopper 5 is provided at the bottom.

When plasticizing, open the shutter 7 and rotate the screw 1 while dropping the raw resin from the hopper 5 into the heating cylinder 2.The raw resin is transferred to the entire heating cylinder 2 while being plasticized, and the other side Skrillyu 1
retreats.

When the metering accumulation is completed, the shutter 7 is closed and the screw 1 moves forward to perform injection.

(Problems to be Solved by the Invention) As described above, when the screw 1 moves forward and the plasticized resin is injected into the mold, the molding is completed. Then, in the next molding cycle, when using another type of resin such as a different colored resin, it is necessary to discharge the resin remaining in the hopper 5, and in this case,
By rotating the hopper rotating device 4, the hopper 5 is moved to the side of the heating cylinder 2.

Then, by opening the shutter 7, the hopper 5
Discharge the raw material resin inside.

In this way, in the conventional example, the raw material resin remaining in the hopper 5 is discharged, but as shown in the figure, the raw material supply port 6 of the housing 3 and the heating cylinder 2
Since the raw resin in the raw material supply port 6 is not discharged, the resin remaining in the raw material supply port 6 will be mixed with new resin of a different type in the next molding cycle, and therefore the resin will not be injected until pure resin is injected. The resin cannot be filled into the mold, and this amount of resin is wasted.

Further, when discharging the resin from the hopper 5, it is necessary to rotate the hopper 5, but this requires securing the space required for the rotation, which makes the work cumbersome.

The present invention has been made to solve the above-mentioned problems, and its object is to provide an injection molding machine that does not waste raw resin and can easily discharge raw resin.

(Means for Solving the Problems) In the present invention, a raw resin discharge port that can be opened and closed is provided at the bottom of the heating cylinder below the raw material supply port.

(Function) When plasticizing the raw resin, after closing the raw resin discharge port, the raw resin is introduced from the raw resin supply port. The charged resin is transferred to the front part of the heating cylinder while being plasticized.

When the plasticization of the raw resin is completed in this way, the screw moves forward and injection is performed.

After injection is completed, open the raw resin discharge port,
The raw resin remaining in the raw resin supply port is discharged to the outside of the heating cylinder through a gap between the inner peripheral surface of the heating cylinder and the outer peripheral surface between the flights of the screw. At this time, a portion of the raw resin remaining in the heating cylinder is also discharged from the raw resin discharge port.

(Example) Examples of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, 10 is a heating cylinder, and 11 is a screw fitted into the heating cylinder 10 so as to be rotatable and reciprocating.

A through hole 12 is formed in the upper part of the side wall at the rear of the heating cylinder 10 .

Further, a housing 13 is fixed to the outer peripheral surface of the rear portion of the heating cylinder 10. A through hole 14 is also formed in the upper part of this housing 13, and this through hole 14 and the through hole 12 of the heating cylinder 10 communicate with each other to form a raw resin supply port 15.

A hopper 16 is fixed to the upper surface of the housing 13, and a discharge port 16a of the hopper 16 is connected to a raw resin supply port 1.
5 are in communication with each other.

A portion of the side wall of the heating cylinder 10 facing the raw resin supply port 15 is cut flat, and a raw resin discharge port 17 consisting of a through hole is formed in this flat portion 10a. Furthermore, a pair of opposing first sliding grooves 18 extending in a direction orthogonal to the axis of the heating cylinder 10 are formed on the inner surface of the raw resin discharge port 17 .

19 is a cylindrical guide with a mounting plate 2 at its base end.
0 is set consecutively. This mounting plate 20 is the heating tube 1
0 and a bottom surface 13b of a recess 13a of the housing 13, which is substantially flush with the flat portion 10a. Housing 13
A second sliding groove 21 connected to the first sliding groove 18 is formed on the bottom surface 13b of the mounting plate 20, and the lower surface 18a, 2 of the first and second sliding grooves 18, 21 is formed on the upper surface of the mounting plate 20.
1a is formed.

A shutter 22 is slidably inserted into the first and second sliding grooves 18 and 21, and is slidably supported by the upper surface of the mounting plate 20. Both end portions of this shutter 22 are bent upward, one forming a grip portion 22a and the other forming a first stopper 22b. Further, a second stopper 22c is formed between both ends of the shutter 22 near the gripping part 22a, and a through hole 22d of approximately the same size as the raw resin outlet 17 is formed between the first and second stoppers 22c. is formed.

The first stopper 22b can freely come into contact with one side of the housing 13, and the second stopper 22b can come into contact with one side of the housing 13.
2c can freely come into contact with the other side of the housing 13, and when the first stopper 22b is in contact with the housing 13 as shown in FIG. On the other hand, when the second stopper 22c is in contact with the housing 13, the through hole 22d does not align with the raw resin discharge port 17, that is, they are not in communication with each other.

Next, the operation of the injection molding machine having the above configuration will be described. First, hold the grip part 22a of the shutter 22 and push the shutter 22 from the position shown in FIG. .

Next, when the raw resin A is introduced from the hopper 16, the raw resin A falls into the heating cylinder 10 from the raw resin supply port 15, and is transferred to the front part of the heating cylinder 10 while being plasticized by the rotating screw 11. On the other hand, the screw 11 is moved back by the resin pressure stored in the front part of the heating cylinder 10.

When the measurement and accumulation is completed in this manner, the plasticized resin is injected into a mold (not shown) by moving the screw 11 forward, and the injection molding is completed.

Then, in the next molding cycle, when using a different type of resin from the previous resin, pull out the shutter 22 in the opposite manner to the above and bring the first stopper 22b into contact with the housing 13 as shown in FIG. By doing so, the through hole 22d of the shutter 22 and the raw resin discharge port 17 are brought into alignment with each other and communicated with each other.

When the raw resin discharge port 17 is opened in this manner, the raw resin A remaining from the hopper 16 to the raw resin supply port 15 and the heating cylinder 10 is removed from the raw resin discharge port 17.
The heat is then discharged to the outside of the heating cylinder 10 through the cylindrical guide 19. In this case, the discharge path of the raw material resin remaining in the hopper 16 is from the hopper 16 to the raw resin supply port 15 to the flight 11a of the screw 11.
The order is: the gap between the outer surface of the gap and the inner surface of the heating cylinder 10 - the raw resin discharge port 17 - the cylindrical guide 19.

When the discharge of the raw material resin A is completed, the raw resin discharge port 17 is closed by pushing the shutter 22 as described above.

(Effect of the invention) As explained above, in the present invention, the raw resin discharge port is formed at the bottom of the heating cylinder, so that the raw resin in the raw material supply port located below the hopper is not only discharged from the raw resin in the hopper. Therefore, the raw resin is not wasted.

Further, when discharging raw material resin, there is no need to rotate the hopper as in the past, and only the raw resin discharge port is opened, so the operation is easy and there is no need to secure the space required for rotating the hopper.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing essential parts of an injection molding machine according to the present invention, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. 3 is a sectional view of a conventional injection molding machine. 10...Heating tube, 11...Skrill, 15...
Raw resin supply port, 17... Raw resin discharge port.

Claims (1)

[Scope of Claim for Utility Model Registration] A raw resin supply port for supplying raw resin is provided at the rear of a heating cylinder into which a screw is inserted so as to be able to rotate and reciprocate, and a raw resin supply port for supplying raw resin is provided at the bottom of the heating cylinder below the raw resin supply port. An injection molding machine characterized by having a raw resin discharge port that can be opened and closed.