JPS60101020A - Screw type injection molder - Google Patents

Abstract

PURPOSE:To prevent the material in an injection nozzle from leaking and dropping due to the remaining pressure when the injection nozzle is moved away from the mold after the injection, by returning an injection plunger to its intermediate position immediately after the material is injected by moving the injection plunger forward, and keeping the injection plunger in said position for a prescribed period. CONSTITUTION:When a main body 1 is lowered to its prescribed position and the tip of an injection nozzle 6 is set to a sprue of a mold 3, a change-over valve 5 is changed to the injection side, and an injection plunger 7 is moved forward by an injection cylinder 8. Thus, the material in an injection chamber 4 is injected from the injection nozzle 6 into the cavity of the mold 3. When the injection plunger 7 reaches the forward end, a limit switch 6L is pushed and then the injection plunger 7 is immediately started to be withdrawn. When the injection plunger 7 is returned to the intermediate positin, a limit switch 7L is pushed, the withdrawing of the injection plunger 7 is stopped to allow it to remain in its intermediate position for a while so that the pressure of the material in the injection nozzle 6 may be allowed to decrease, thereafter the change-over valve 5 is changed to the filling side and the main body 1 is lifted up.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a complete screw injection molding machine for injection molding rubber or the like.

In a prebra type screw injection molding machine with a screw dedicated for J+L plasticization equalization, material injection and filling are switched by a switching valve, and the material injection is stopped by the pushing operation of the injection plunger, and then immediately Control is performed 91 to fill the injection chamber with the material 4 by switching the changeover valve 91, and to separate the injection nozzle from the mold.

However, after injection, the injection pressure of the material remains in the closed injection nozzle for a while, so when the injection nozzle is removed from the mold.

When the injection nozzle comes into contact with the mold during the next injection, a gap is created between the sprue bush and the end of the nozzle, and the injection material falls there. There was a problem that the fortune-telling material leaked from the mold or mixed into the injection material, causing molding defects.

The present invention includes 1. This was done to solve the problem described above, and when the injection nozzle is removed from the mold after Q4 exit, it prevents the material from leaking due to the residual pressure of the material in the nozzle. 11. The purpose is to provide a screw set q+ extrusion molding machine that performs molding ((I).

For this purpose, one aspect of the present invention is to provide an injection sill for driving an injection plunger fitted into an injection chamber in the main body, and a Q
1. A screw that converts the output material 4 into it (qf) and supplies it, a communication state fl between the screw and the Q4 exit nozzle to the exit chamber, a switching go r that changes the direction, and a switch y1 that changes the In a screw set injection molding machine equipped with a sequence control circuit that executes the fA4 +li- filling of the protrusion 1'1. Move forward and inject material '1, then move the q4 output plunger to the intermediate position.

A sequence control 1 "!1 path is configured to return the injection plunger to an intermediate (<, ++, Configured.

The embodiments of this invention will be described above based on the drawings.

Figure 1 shows a vertical cross-section of Prebrata Eve's screw set injection molding machine, where l is the main body and 1-+
1 is connected to the tip of the screw inlet 2a of the fixed fluid pressure sill 2, and the mold 3 installed in the F direction is
make a move. A cylindrical injection chamber 4 is formed in the main body 1, and the tip of the injection chamber 4 is connected to an injection nozzle 6 in the F section via a switching valve 5. The injection plunger 7 is connected to the injection sill 8, advances into the injection chamber 4 by its extrusion motion f1, and injects the material 1 in the injection chamber 4 into the mold 3 through the injection nozzle 6. 9 is a material plasticizing screw installed on the opposite side of the injection syringe 8 to the main body l, which plasticizes the material introduced inside, and converts (v) (11 through F5).
11 is connected to fill the outlet chamber 4. The switching valve 5 is a rod-shaped valve that slides inside the main body in a direction perpendicular to the plane of the paper in FIG. 1. As shown in FIG. The injection chamber 4 and the screw 9 are
Switch the Oki-dori connection state to k.1 to the injection nozzle 6 of . Furthermore, 1 of 1 body 1. Mitswitch 5L detects yl and protrusion, 2r-111 pull-back position of plunger 7, push-out S〆ri (Ill exit 1f!i), and intermediate pull-back, +77, respectively. , 6L, 7L, and the switching states of the switching valve 5 at the time of injection and before filling are detected, respectively.Mitswitches 3L, 4L are installed at necessary locations, respectively.

Figure E3 shows the sequence control circuit of the Q4 molding machine.
The control circuit includes relays OR~8R and timer relays 17~6.
and their contact points, 1. 6 contact-51 of the limit switches IL to 7L that detect the movement f'1 state fff of the moving part 1'1, and the fluid pressure sill 10 for the switching block 5 drive.
The solenoid IS that controls the 144 output cylinder 8 (
311 solenoid I・23.33, screw 9 i
JI 1Jll solenoid 4S and main body l y
The timer relay I T' is connected to the solenoids 5S and 6S that control the fluid pressure cylinder 2, and is configured to operate the injection molding machine in a predetermined order as described later. A protruding wound! /J Kanbu”
The time t until the switching valve 5 switches to the injection side is set to, for example, 10 seconds, and the timer relay 2T is set to a time L2, for example, 4 seconds until the injection plunger 7 moves forward after the switching valve 5 is switched to the injection side. , timer relay 3T is body 4
After the exit plunger 7 advances +tij and completes injection, the time t3 until the screw 9 starts the filling operation is 12, for example.
Set to 0 seconds. Further, the timer relay 4T is set to a time t4, for example, 20 seconds, after the injection plunger 7 is returned to the intermediate position until the switching block is switched to the filling position, and the timer relay 6T is set to a time t4, for example, 20 seconds, after the injection plunger 7 is returned to the intermediate position. The time t6 until the main body 1 is turned on after it is turned on is set to, for example, 10 seconds.

Next, the operation of the complete screw injection molding machine will be explained.

First, when the start switch S is turned on with the main body l in the upper y1 position, the switching gong r5 in the filling position, and the injection plunger 7 in the retracted position, the limit switch IL is pressed and the contact lL1 is turned on. Because of this, relay ORI,
OR2 and OR3 are turned on, and the solenoid 6S is operated to push out the fluid pressure cylinder 2 or piston rod 2a, and the main body 1 is lowered to a predetermined position (1), and the tip of the Q1 output nozzle 6 is attached to the sprue of the mold 3. 1. Then, limit switch 2L is pressed and its contact turns on, timer relay 1 starts to run, and after set time 1, time limit contact 1H,,l T l turns on, and relay In When energized, contact 1.R2 turns off, solenoid IS operates, and the fluid pressure cylinder 10 is pushed out!
l] exchange M 5 is exchanged by injection@1 νJ. This 11
j+, limit switch 4L operates and its contact 4L1
．． Since 4L2 is turned on, two timer relays start running I, and after the set time t2, time limit contact 2Tl is turned on, relay 2R is turned on, and its contacts 2R1 and 2R are turned on.
2 is turned on, so the solenoid 2S is activated and the injection cylinder 8 moves the injection plunger 7 forward. As a result, the material in the injection chamber 4 is injected from the outlet nozzle 6 into the cavity of the mold 3. When the injection plunger 7 reaches the ejection end, the limit switch 6L is pressed and its contact 6L1 Since is turned on, relay 3R is energized,
When the contact 3R4 is turned on, the solenoid 3S is activated and the injection plunger 7 immediately moves backward. The injection plunger 7 is located at the middle Bf, , i, (for example, approximately 3 cm from the extrusion end)
m), limit switch 7L is pressed and its contact 7L turns on, turning on relay 4R.
j force, the b contact 4R2 turns off and solenoid 1:3
S is deenergized, the injection plunger 7 stops retreating and stands still at that position, and this state continues for a set time L3 of the timer relay 3T. On the other hand, when point 7L1 is turned on at 4, timer relay 4T starts to run 1, and after the set time t4, time limit contact 4Tl is turned on. Since IR is deenergized and its b contact IR2 is turned on, the solenoid IS is deenergized to zero, the fluid pressure cylinder 10 performs a pullback operation, and the switch J switch r5 is switched to the filling side. This state is maintained until the material in the mold 3 completes vulcanization or solidification, that is, until the set time of the timer relay 3T has elapsed. During this time, the five timer relays are activated and their contacts 5T1 are turned on. . When timer relay 3T times up, its contacts 3Tl and 3T2 turn on, and relay 6R switches to 4.
Since the contact 6R2 is turned on, the solenoid 4S is turned on and the screw 9 is started, and the screw 9 is turned on.
The injection chamber 4 in the main body l is filled with +rl plasticized material 1. At this time, the injection plunger 7 is automatically pushed back by the filling pressure of the material, and when the injection plunger 7 retreats (returns to Q- and the filling is completed, the limit switch 5
L is operated, and the JD point 5L2 is turned off, the solenoid 4S is deenergized, and the screw 9 is stopped. do. When this limit switch 5L is activated, its contact 5Ll
When turned on, the six timer relays start counting, and the set time 1. Afterwards, the time limit contact 6T1 is turned on. Then, the relay 7R is energized, its contact 7R2 is turned on, and the relay 1:5S is energized, so that the fluid pressure cylinder 2 pulls back the piston rod 2a, and the main body 1 moves to a predetermined position. The limit switch IL is pressed and its contact IL2 is turned on. This energizes the relay 8R for injection molding path -r, and
Contacts 8R1 to 8R5 turn off, relays 0R13R and 4R
, 5R17R are all deenergized and kn of the main body 1 is stopped (), the entire control circuit is reset and one automatic rotation of injection molding ends. After returning to the intermediate position 4 and maintaining this state for a while to reduce the material pressure in the injection nozzle 6, the switching valve 5 is switched to move the main body 1 to 1. At time A, the tip of the injection nozzle 6 is in the mold 3
It is possible to prevent the J rice 1 from leaking down from the injection nozzle 6 when it is separated from the injection nozzle 6.

Below 1. As explained, according to the present invention, after the material pressure in the injection nozzle is reduced after injection molding, the injection nozzle is separated from the mold, so that the material in the J11 exit nozzle leaks out from the female 11 port. In addition, unlike the conventional method, leaked material does not get caught at the tip of the sprue bushing.
;A L,, it is possible to prevent material leakage by creating a gap between the sprue bush and the nozzle 11 during the next injection, and to prevent molding defects caused by the fortune-telling material getting mixed into the ejection material.

[Brief explanation of drawings]

ti shows an embodiment of the present invention, FIG. 1 is a vertical sectional view of a screw set 91 extrusion molding machine, FIG. 2 is a right side view of the same, FIG. 3 is a sequence control circuit diagram, and FIG. , Char 1. 1... Main body, 4... Injection chamber, 5... Gino exchanger, 6... Injection nozzle, 7... Q4 output plunger, 8... 14 output shilling, 9.・Screw, IL
~7L...Limit switch, 0'r~6T...Timer relay. Q+I, M Applicant: H Synthetic Co., Ltd. Figure 1

Claims (1)

[Claims] An injection sill that drives an injection plunger that is inserted into an injection chamber in the main body, and an injection material that is inserted into the injection chamber.
A screw for supplying fj and a screw for the discharge chamber ('4 II! νJ switching block C for switching the communication state of the nozzle, and a mold for the liA main body) l
Descending A'1.4 Injection of charge - 1M? , and a sequence control circuit that executes each operation of the νJ change valve at f, r, ll, and rl. a detection stage configured to configure the sequence control circuit to return the injection plunger to an intermediate position, and detect a state in which the injection plunger has returned to the intermediate position;
A screw-injection molding machine that uses a timer that maintains the returned state for a predetermined period of 11ν as a #I sign when the timer goes down.