KR100560671B1 - Ball Valve Screw-Head Device For Flowing Backward Prevention - Google Patents

Abstract

The present invention relates to a backflow prevention ball valve screw-head device installed in the injection molding machine. To this end, when molten resin is fed by the rotation of the screw, a ball valve that blocks the flow path of the screw-head is raised to open the flow path, and the screw When the rotation is stopped, the ball valve which opens the flow passage descends due to the phase difference, and blocks the flow passage, thereby preventing the filling pressure of the molten resin, which has been filled inside the barrel, from flowing back toward the screw side.

Injection machine, screw, weight, ball valve, flow path, spacer, bearing,

Description

Ball Valve Screw-Head Device For Flowing Backward Prevention

1 is a cross-sectional configuration view showing a conventional screw-head device built in the barrel of the injection machine,

2 is a block diagram of an injection machine installed with a backflow prevention ball valve screw-head device according to the present invention,

3 is an enlarged view illustrating a state in which the screw-head according to the line A of FIG. 2 is enlarged;

Figure 4 is a block diagram showing a state in which the flow path of the non-return ball valve screw-head device according to the present invention opened;

Figure 5 is a block diagram showing a state in which the flow path of the backflow prevention ball valve screw-head device according to the present invention is blocked.

<Description of the code | symbol about the principal part of drawing>

3: screw-head,

3a: first euro, 3b: second euro,

3c: ball valve, 3d: coil spring,

5: barrel, 7: screw,

10: spacer, 11: groove,

11a: bearing, 12: first euro,

13: screw connection, 20: screw-head,

21: Euro 2, 22: Euro 3,

23: Euro 4, 24: Euro 5,

24a: ball valve, 25: sixth euro,

30: screw, 40: weight,

100: screw-head unit, 200: injection machine,

210: barrel 220: hopper

The present invention relates to a screw-head device that can prevent the reverse flow caused by the filling pressure of the molten resin filled in the barrel as the feeding of the molten resin is stopped due to the rotation stop of the screw, more specifically the screw When the molten resin is pushed by the rotation of the ball valve, the ball valve blocking the flow path of the screw-head rises to open the flow path, and when the rotation of the screw stops, the ball valve opening the flow path descends due to the phase difference and blocks the flow path. The present invention relates to a non-return ball valve screw-head device capable of preventing the molten resin filled in the barrel from flowing back to the screw side.

In general, the screw of the injection molding machine melts the thermoplastic resin supplied through the hopper by the heat of heaters mounted on the barrel and the mechanical energy of the screw, so as to press the thermoplastic resin at a pressure and a speed suitable for the molding conditions in the mold.

Such a screw melt-feeds the thermoplastic resin which is built up inside the barrel of the injection molding machine.

The thermoplastic resin thus compressed is filled to one side of the barrel through a screw-head connected to one end of the screw. At this time, when the filled molten resin is filled by a certain capacity, a filling pressure is generated. When the filling pressure is greater than the preset back pressure of the screw, the screw moves to the hopper direction, that is, to the other side, after which the screw stops rotating and is formed. The molten resin is extruded into the mold by moving to one side at a pressure and a speed suitable for the conditions.

However, the molten resin filled in one side of the barrel at the time when the rotation of the screw stops, there was a problem that the molten resin flows back through the head of the screw due to the filling pressure. Accordingly, a deviation occurs depending on the amount of molten resin filled in the barrel during injection, resulting in a problem of dimensional instability of the injection molded product and weight deviation of the injection molded product.

In order to prevent this, the conventional ball valve screw-head has been used, but this also causes other problems.

This problem will be described in detail with reference to the accompanying drawings below.

1 is a cross-sectional view showing a conventional screw-head built in the barrel of the injection molding machine. As shown in FIG. 1, the screw-head 3 is configured to be fixed to a screw 7 arranged in the barrel 5 so that it can be co-rotated.

A plurality of first flow passages 3a are formed in both ends of the screw-head 3 so that the molten resin, which is pushed through the screw 7, may be filled to one side of the barrel 5.

Here, each of the first flow passages 3a is connected to a single second flow passage 3b formed inside the center of the screw-head 3 to communicate with each other. At this time, a ball valve 3c is inserted into the second flow passage 3a. The ball valve 3c is formed by the elastic energy of the coil spring 3d fixed to one side of the second flow passage 3a. It is a structure that blocks (3b).

This structure blocks the second flow path 3b when the molten resin, which is pushed in accordance with the rotation of the screw 7, is transferred to the second flow path 3b through the first flow path 3a of the screw-head 3. The ball valve 3c which is present is forcibly moved to one side to open the first flow passage 3a. As a result, the molten resin is filled with one side of the barrel 5 via the first flow passage 3a and the second flow passage 3b formed inside the screw-head 3.

When the filling of the molten resin filled in this way is completed, the screw 7 stops rotating, and the molten resin stops feeding, so that the ball valve 3c of the second flow path 3b is elastic to the coil spring 3d. The rest of the first flow path 3a is blocked by the restoring force. Therefore, the reverse flow of the molten resin is prevented.

However, this structure, when the elastic spring of the coil spring (3d), it is easy to stick the molten resin throughout the coil spring (3d), may cause a problem that the molten resin is carbonized due to the high temperature.

In addition, since the screw-head 3 operates at about 200 ° C. or more, the durability of the coil spring 3d gradually decreases as time passes, thereby reducing the life of the screw-head 3 as a whole.

In addition, the ball valve (3c) is changed depending on the supply state of the molten resin, viscosity, temperature and acceleration of the screw (7), etc. According to this change, the molten resin filled to one side of the barrel (5) has a change in the filling amount This results in problems of weight variation and dimensional stability of the injection molded product.

Therefore, in view of the above problems, the present invention has led to the development of a screw-head structure in which a ball valve which is moved up and down automatically by a phase difference can open and close a flow path when the feeding of the molten resin is stopped.

Therefore, the present invention has been made in view of the above-described conventional problems, and the first object of the present invention is to fill the pressure of the molten resin filled in the barrel as the feeding of the molten resin is stopped due to the rotation stop of the screw. It is to provide a non-return ball valve screw-head structure that can prevent the occurrence of the reverse flow action.

The second object of the present invention is that when the molten resin is pushed by the rotation of the screw, the ball valve blocking the flow path of the screw-head rises to open the flow path, and when the rotation of the screw stops, the ball valve was opened. It is to provide a backflow prevention ball valve screw-head device having a structure capable of preventing the flow of the molten resin filled in the barrel back to the screw side by blocking the flow path is lowered by the phase difference.

The object of the present invention, in the screw-head 20 built in the barrel 210 of the injection machine 200,                         

It is fixed to one end of the screw 30 is rotated and interlocked, and includes a bearing (11a) is placed in shape corresponding to the groove portion 11 formed on the other end, the molten resin to be discharged from the screw 30 is discharged to one side A spacer 10 having a first passage 12 through which a plurality of inlets pass through the circumferential direction of a single outlet formed on the groove 11 so as to be oriented, and accompanying the rotation of the spacer 10. The second passage 21, which is prevented from rotating and penetrates into the other side, is installed in the bearing 11a placed in the groove 11 so as to communicate with the first passage 12.

A fourth flow passage 23 which communicates vertically with one side of the second flow passage 21 so that the molten resin can be pushed into the barrel 210 through the third flow passage 22 formed through the inside of the one side; On the other side of the fourth passage 23 and the other side of the fifth passage 24 and the fifth passage 24 which communicates perpendicularly to the other side of the third passage 22 at the same height as the four passages 23. The fifth flow path 24 to open and close the fifth flow path 24 in accordance with the screw-head 20 consisting of the sixth flow path 25 in horizontal communication and the pressure of the molten resin is fed from the screw 30 It comprises a ball valve (24a) to be inserted into, the fixing means mounted to the lower portion of the screw-head 20 so that the position of the screw-head 20 can be fixed; It is achieved by a non-return ball valve screw-head device, characterized in that it comprises a.

When the ball valve 24a stops the feeding of the molten resin due to the rotational stop of the screw 30, the ball valve 24a is preferably moved up and down by the phase difference to block the fifth flow passage 24.

In order to prevent separation of the inlet ball valve 24a from the above, the fifth passage 24 preferably has a larger inner diameter than the respective passages 22 and 25.

One end of the fifth flow passage 24 is preferably extended to a position higher than the third flow passage 22 so that the third flow passage 22 can be opened by the rise of the inboard ball valve 24a. Do.

Preferably, the fixing means is a weight 40 made of a material having a specific gravity greater than that of the head material.

Other objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and the preferred embodiments associated with the accompanying drawings.

In general, the screw built in the barrel is operated by measuring the molten resin, and extruding the weighed molten resin to the outside of the barrel and discharged into the mold.

The present invention is a ball for preventing backflow to prevent the flow of molten resin back to the screw through the flow path of the screw-head before the process of extruding the molten resin filled in the barrel to the outside of the barrel, that is, when the screw is stopped A valve screw-head device.

Hereinafter will be described with reference to the accompanying drawings, a ball valve screw-head for preventing a reverse flow according to the present invention.

Figure 2 is a block diagram of the injection machine is installed with a non-return ball valve screw-head device according to the present invention, Figure 3 is an enlarged view showing an enlarged view of the screw-head according to the line A of FIG. As shown in FIGS. 2 and 3, the screw-head 20 is connected to one end of the screw 30 built in the barrel 210 so that the thermoplastic resin introduced into the hopper 220 can be discharged into the mold. It is attached.

The screw-head device 100 is largely composed of two parts. The screw 10 is screwed to one end of the screw 30 and rotates together with the screw 10, and the screw-head 20 arranged at one end of the spacer 10. It consists of.

In this case, the spacer 10 is fixed to one end of the screw 20 so that the screw coupling portion 13 is extended to the other end, and the first end of the circular shape for accumulating the screw-head 20. The groove part 11 is formed.

In addition, the groove 11 has a bearing 11a corresponding to the shape so that the other side of the screw-head 20 can be arranged. This structure is a bearing (11a) coupling structure in which the screw-head 20 can be prevented from the accompanying rotation due to the rotation of the screw 30 and the spacer 10.

In addition, a first flow passage 12 penetrates the inside of the spacer 10 so that the molten resin, which is pumped from the screw 30, may be transferred to the screw-head 20. The first passage 12 has a structure in which a plurality of inlets are separated along the circumferential direction toward the other side with a single outlet formed in the center of the groove 11.

In addition, the screw-head 20 is formed with a second flow passage 21 penetrating into the other side to communicate with the outlet of the first flow passage 12 formed on the groove portion 11 of the spacer 10, In one side, the third passage 22 formed through the second passage 21 is formed to penetrate through.

In addition, the molten resin can be discharged to the inside of the barrel 210 through the third passage 22 so as to be vertically communicated with one side of the second passage 21 and the other side of the third passage 22 at the same height. The fourth flow path 23 and the fifth flow path 24 are formed. At this time, the sixth flow path 25 for connecting the fourth flow path 23 and the five flow paths 24 is configured to communicate with the other side of the fourth flow path 23 and the five flow paths 24.

Accordingly, the molten resin that is fed from the screw 30 is sequentially fed through the first passage 12 of the spacer 10 to the two passages 21 of the screw-head 20 and communicated with the second passage 21. It is configured to be discharged into the barrel 210 through the sixth channel 25, the fifth channel 24, the third channel 22 via the four channels 23.

Here, the second flow passage 21 and the third flow passage 22 of the screw-head 20 are located on the same horizontal line.

In addition, the fifth channel 24 communicating with the third channel 22 vertically has a ball valve 24a so that the fifth channel 24 can be opened and closed depending on whether or not the molten resin is pumped from the screw 30. It is built in.

Here, the ball valve 24a is moved downward by the phase difference when the pumping of the molten resin stops due to the rotational stop of the screw 30, thereby blocking the fifth flow passage 24. At this time, the diameter of the ball valve 24a is zero. It has a diameter relatively larger than the inner diameters of the third flow path 22 and the sixth flow path 25 connected to one side and the other side of the five flow paths 24, respectively, so that it does not escape to other flow paths 22 and 25, Accordingly, the fifth passage 24 has an inner diameter relatively larger than the diameter of the ball valve 24a so that the ball valve 24a can be freely moved according to the phase difference.

In addition, one end of the fifth passage 24 extends to a position relatively higher than the third passage 22 so that the fifth passage 24 can be opened by the rise of the embedded ball valve 24a. This structure is a structure in which the third passage 22 can be opened at the highest point of the ball valve 24a because the other side of the third passage 22 is located on the movement path of the ball valve 24a.

On the other hand, the screw-head 20 is fixed to the lower portion so that the position can be fixed without accompanying rotation in accordance with the rotation of the screw 30 and the spacer 10.

The fastening means is fixed to the center of gravity of the screw-head 20 toward the ground weight weight consisting of a material having a high specific gravity capable of fixing the phase of the ball valve (24a) embedded in the fifth passage (24) It is preferable that it is (40).

Figure 4 is a block diagram showing an open state of the flow path of the backflow prevention ball valve screw-head device according to the present invention. As shown in FIG. 4, in the screw-head apparatus 100, the ball valve 24a of the screw-head 20 is lifted by the pressure of the molten resin that is pushed in accordance with the rotation of the screw 30 so that the fourth passage ( 23) is open.

In this state, the spacer 10 screwed to the screw 30 is rotated together with the rotation of the screw 30, and the screw-head 20 built in the spacer 10 is fixed to the bearing 11a. The position is fixed without being rotated. At this time, the position fixing of the screw-head 20 will be more certain due to the weight 40 mounted on the bottom.

The filling of the molten resin first passes through the second channel 21 of the screw-head 20 through the first channel 12 of the spacer 10 according to the rotation of the screw 30.

The molten resin having passed through the second flow passage 21 is pumped up to the fourth flow passage 23. At this time, the ball valve 24a embedded in the fifth flow passage 24 connected to the third flow passage 22 is raised to open the third flow passage 22 and the barrel 210 through the third flow passage 22. The molten resin is metered inside.

Figure 5 is a block diagram showing a state in which the flow path of the backflow prevention ball valve screw-head device according to the present invention is blocked. 5 illustrates a state in which the rotation of the screw 30 is stopped before extruding the molten resin filled in the barrel 210.

When the rotation of the screw 30 is stopped as described above, the feeding of the molten resin stops, and at this time, the molten resin filled into the barrel 210 flows back to the screw with a low filling pressure.

At the same time, when the rotation of the screw 30 stops and the pumping of the molten resin stops, the ball valve 24a that is raised moves downward by the phase difference to block the fifth flow passage 24, and thus, the screw side The molten resin that flows back can no longer flow back on the fifth flow passage 24 and stops.

In addition, the screw 30 and the screw-head 20 inject (discharge) the molten resin filled in the barrel 210 into a mold connected to the outside of the barrel 210, that is, the outside of the barrel 210. .

As described above, according to the non-return ball valve screw-head device according to the present invention, the phenomenon that the molten resin flows back through the screw-head is blocked, so that the amount of the molten resin injected is constant, and thus the dimensional stability of the injection-molded product There is an advantage that the injection molding having a uniform dimension and weight is injected without a weight deviation occurs.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, various other modifications and variations may be made without departing from the spirit and scope of the invention. Accordingly, it is intended that the appended claims cover such modifications and variations as fall within the true scope of the invention.

Claims (5)

In the screw-head 20 built in the barrel 210 of the injection machine 200, It is fixed to one end of the screw 30 is rotated and interlocked, and includes a bearing (11a) that is placed in shape corresponding to the groove portion 11 formed on the other end, the molten resin pumped from the screw 30 is discharged to one side A spacer 10 formed with a first passage 12 through which a plurality of inlets pass through the circumferential direction about a single outlet formed on the groove 11 to be formed; A bearing placed in the groove 11 to prevent the accompanying rotation due to the rotation of the spacer 10 and to communicate with the first channel 12 through which the second channel 21 penetrates into the other side ( In 11a), A fourth flow passage 23 which communicates vertically with one side of the second flow passage 21 so that the molten resin can be pushed into the barrel 210 through the third flow passage 22 formed through the inside of the one side; On the other side of the fourth passage 23 and the other side of the fifth passage 24 and the fifth passage 24 which communicates perpendicularly to the other side of the third passage 22 at the same height as the four passages 23. A screw-head 20 composed of sixth flow passages 25 in horizontal communication; And And a ball valve 24a inserted into the fifth channel 24 so that the fifth channel 24 can be opened and closed according to whether or not the molten resin is pumped from the screw 30. Fixing means mounted to the lower portion of the screw-head 20 to fix the position of the screw-head 20; Backflow prevention ball valve screw-head device, characterized in that comprising a. The method of claim 1, wherein the ball valve (24a) is moved up / down by the phase difference when the pumping of the molten resin stops due to the rotational stop of the screw 30, characterized in that for blocking the fifth passage (24) Backflow ball valve screw-head device. 2. The backflow prevention ball valve according to claim 1, wherein the fifth flow passage 24 has an inner diameter relatively larger than each of the flow passages 22 and 25 to prevent the inflow of the ball valve 24a. Screw-head unit. The method according to claim 1 or 3, One end of the fifth flow passage 24 is extended to a position higher than the third flow passage 22 so that the third flow passage 22 can be opened by the rising of the inboard ball valve 24a. Backflow ball valve screw-head device. 2. The backflow prevention ball valve screw-head device according to claim 1, wherein the fixing means is a weight (40) made of a material larger than the specific gravity of the screw head.

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