JPH0520512Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a resin plasticizing device for an injection molding machine that plasticizes resin and injects it into a mold.

[Conventional technology]

As a resin plasticizing device for an injection molding machine, the device shown in FIG. 3 is known.

In this plasticizing device, a screw 3 is inserted into a heating cylinder 2 having a nozzle 1 at one end and a resin supply hole 2a formed at the other end, and an intervening member 4 such as a heating cylinder support is inserted into the resin supply hole 2a. Communication hole 4a formed in
The hopper 5 is communicated through the hopper 5. Then, while supplying the resin in the hopper 5 into the heating cylinder 2 through the communication hole 4a and the resin supply hole 2a, the screw 3 is rotated in the circumferential direction by a hydraulic motor (not shown) or the like to plasticize the resin. , by moving the screw 3 forward using a hydraulic cylinder (not shown) or the like, the plasticized molten resin is transferred to the mold 6.
eject into.

In addition, in FIG. 3, reference numeral 7 denotes an opening/closing shutter, and a slide groove 5a formed at the bottom of the hopper 5
The opening 7b allows the hopper 5 to communicate with the communication hole 4a while the closing portion 7a disconnects the communication hole 4a from the hopper 5. 8 is ~.

[Problem that the invention aims to solve]

In an injection molding machine, if there is a risk that the resin will decompose or deteriorate when injection molding is stopped or stopped, or if the resin is changed or the color is changed, or the heating cylinder 2 is cleaned the day before a holiday, etc. Usually, if
A purge agent (replacement resin) and a cleaning agent are put into the heating cylinder 2 to clean the inside of the heating cylinder 2.

However, in the conventional resin plasticizing apparatus described above, there is only one communication hole 4a that communicates the inside of the heating cylinder 2 with the outside, so when putting the purging agent or cleaning agent into the heating cylinder 2, It is necessary to take out the resin in the hopper 5 and empty the hopper 5, and then pour the purging agent or cleaning agent into the heating cylinder 2 through the hopper 5, or to remove the hopper 5 and pour it into the heating cylinder 2 through the communication hole 4a. However, there is a problem that it takes time and effort.

In addition, if air that enters the heating cylinder 2 together with the resin during operation of the plasticizing device or gas generated during the melting of the resin is mixed into the resin without being released to the outside, molded products may be defective. Since there is a risk that the generated gas may cause harmful effects such as corrosion of the heating cylinder 2, screw 3, etc., it is necessary to efficiently discharge the air and gas to the outside.

However, in the conventional plasticizing apparatus described above, only one communication hole 4a opens the heating cylinder 2 to the outside, and furthermore, the communication hole 4a is always filled with resin. Therefore, there is a problem in that air and gas escape is difficult, and molded products as described above are likely to be defective and the heating cylinder 2 and the like are likely to be corroded.

In addition, a heating cylinder with two independent main and secondary hoppers (Japanese Unexamined Patent Publication No. 58-69010), and a heating cylinder with a hopper with separate pigment supply holes (Unexamined Japanese Patent Application Publication No. 1983-69010) (Japanese Unexamined Patent Publication No. 1-115617) has been proposed.

However, all of the above-mentioned plasticizing devices have a structure in which a sub-hopper, pigment supply hole, or gas discharge hole is provided independently in the heating cylinder.
A new problem arises in that the structure becomes more complicated.

This invention allows for easy injection of purging agents and cleaning agents into the heating tube, as well as efficient removal of air and gas from the heating tube while preventing dust from entering the resin. The purpose is to provide a plasticizing device.

[Means to solve the problem]

In order to achieve the above object, the present invention has a screw inserted into a heating cylinder having a nozzle at one end and a resin supply hole formed at the other end, and a hopper communicating with the resin supply hole through a communication hole. In the plasticizing device for resin in an injection molding machine, a branch hole is connected to the communication hole by branching from the communication hole, and a check valve body having a valve seat inside is detachably attached to the open end of the branch hole. It is installed in the check valve body, closes the branch hole by contacting the valve seat with its own weight, and when air pressure or gas pressure is applied to the branch hole side, it moves upward from the valve seat and prevents air or gas from flowing outside. A check ball is freely inserted vertically to allow free flow, and a lid with a filter is detachably attached to the upper end of the check valve body.

[Effect]

When plasticizing the resin, the resin is placed in a hopper and supplied to the heating cylinder through the communication hole, as in the conventional method, and the screw is rotated. At this time, air that has entered the heating cylinder together with the resin and gas generated during plasticization of the resin are discharged to the outside through the branch hole.
Unlike the communication holes that serve as resin passages, the branch holes are not filled with resin, so the air and gas within the heating cylinder are efficiently discharged to the outside from the branch holes.

Moreover, when cleaning the inside of the heating cylinder, a purge agent or a cleaning agent is poured into the heating cylinder through the branch hole. Therefore, there is no need to take out the resin from the hopper and empty the hopper, or to remove the hopper, and the heating cylinder can be cleaned easily and quickly.

The filter filters out dust from the atmosphere, and the check ball stops the atmosphere, so no dust will enter the heating cylinder during plasticization of the resin. When pouring purging agent or cleaning agent into the heating cylinder through the branch hole, the check ball can be easily removed and the check valve body can be used as a hopper.

〔Example〕

1 and 2 show an embodiment of the present invention. The basic structure of the resin plasticizing device in this injection molding machine is the same as the conventional plasticizing device shown in FIG.

That is, the screw 3 is inserted into the heating cylinder 2 which has a nozzle (not shown) at one end and a resin supply hole 2a at the other end, and the hopper 5 communicates with the resin supply hole 2a through the communication hole 4a. has been done. The communication hole 4a is bored in the intervening member 4, and the opening/closing shutter 7 having a closing part 7a and an opening part 7b is slidably inserted into the slide groove 5a at the bottom of the hopper 5.

In the plasticized resin according to the present invention, a branch hole 4b is provided on the nozzle side of the intervening member 4 (left side in FIGS. 1 and 2) branching from the communication hole 4a. The branch hole 4b extends obliquely upward from the lower part of the communication hole 4a, and its opening end is a screw hole 4c. In the plasticizing apparatus shown in FIG. 1, a check valve body 9 is inserted into the screw hole 4c of the branch hole 4b.
is removably screwed into the check valve body 9, and a relatively lightweight check ball 10, such as a ping pong ball, is inserted into the check valve body 9 so as to be able to freely move up and down. The check ball 10 contacts the valve seat 9a provided in the check valve body 9 under its own weight to close the branch hole 4b, and also separates upward from the valve seat 9a when air pressure or gas pressure is applied to the branch hole 4b side. Allowing air and gas to flow freely to the outside. A lid 12 having a filter 11 is removably screwed onto the upper end of the check valve body 9.

The check valve main body 9 can be replaced with a sub-hopper 13 as shown in FIG. The sub-hopper 13 is detachably attached to the intervening member 4 with bolts 14. A slide groove 13a is provided at the bottom of the sub-hopper 13, and the slide groove 13a has a closed part (not shown) and an opening part 1.
An opening/closing shutter 15 having a number 5b is slidably inserted therein. The opening/closing shutter 15, like the opening/closing shutter 7, cuts off the communication between the branch hole 4b and the sub-hopper 13 at the closing part, and allows the sub-hopper 13 to communicate with the branch hole 4b at the opening part 15b.

Next, the operation of the resin plasticizing device in the injection molding machine according to the present invention configured as described above will be explained.

FIG. 1 shows a check valve main body 9 screwed into a screw hole 4c of a branch hole 4b, and a check ball 1 inserted therein.
0, the lid 12 with a filter is screwed onto the upper end of the check valve body 9, and the opening/closing shutter 7 is moved to communicate the hopper 5 with the communication hole 4a through the opening 7b. In this state, the resin in the hopper 5 is spread between the opening 7b and the communication hole 4.
a, the resin is supplied into the heating cylinder 2 through the resin supply hole 2a, and is plasticized by the rotation of the screw 3.

In this case, the air that entered the heating cylinder 2 together with the resin and the gas generated during plasticization of the resin pass through the resin supply hole 2a and the lower part of the communication hole 4a to the branch hole 4.
b, and pass through check ball 10 to filter 1.
1 and exits to the outside. Since the branch hole 4b is empty and has low flow resistance, air and gas can escape smoothly to the outside. The check ball 10 and the filter 11 prevent dust and the like floating in the atmosphere from entering the branch hole 4b.

When cleaning the inside of the heating cylinder 2 by adding a purge agent or cleaning agent, remove the check valve main body 9 from the intervening member 4, attach the sub hopper 13 to the intervening member 4 with bolts 14 as shown in FIG.
Close the hopper 5 with the closing part 7a of the opening/closing shutter 7,
Purge agent and cleaning agent are transferred from sub-hopper 13 to branch hole 4.
into the heating cylinder 2 through b. Check valve body 9
and sub hopper 13 is smaller than hopper 5,
Moreover, since it is lightweight, it is extremely easy to attach and detach the check valve main body 9 and the sub-hopper 13, and there is no need to empty the large hopper 5 by taking out the resin.
Workability is good. If necessary, it is also possible to introduce a coloring agent or the like through the branch hole 4b.

Depending on the amount and type of purging agent, cleaning agent, coloring agent, etc., the check ball 10 can be pulled out from the check valve body 9 and the check valve body 9 can be used as a sub-hopper. Therefore, the sub-hopper is not essential in the present invention.

[Effect of idea]

As explained above, in the resin plasticizing device of the injection molding machine of the present invention, a screw is inserted into a heating cylinder that has a nozzle at one end and a resin supply hole formed at the other end, and communicates with the resin supply hole. In a plasticizing apparatus for resin in an injection molding machine in which a hopper is communicated with a hopper through a hole, a branch hole is branched from the communication hole and communicated with the communication hole, so that the heating cylinder is connected with the resin. Air that has once entered the interior and gas generated during plasticization of the resin can be efficiently discharged to the outside from the branch hole. Therefore, molded products are prevented from being defective due to entrainment of air and gas, and corrosion of the heating cylinder and screw due to gas is also prevented.

In addition, when cleaning the heating cylinder, purging agent or cleaning agent can be put into the heating cylinder through the branch hole without draining the resin inside the hopper and emptying the hopper, or removing the hopper. Cleaning work can be done quickly and easily. Since it is only necessary to drill a branch hole, the structure does not become complicated, and it can be easily implemented in an existing plasticizing device.

Further, in the present invention, a check valve body having a valve seat inside is detachably attached to the open end of the branch hole, and the check valve body has a check valve body that contacts the valve seat with its own weight to close the branch hole. In addition, when air pressure or gas pressure is applied to the branch hole side, a check ball is inserted so as to be able to move up and down, moving upwards from the valve seat and allowing air or gas to flow to the outside. A lid equipped with a filter is removably attached to the upper end of the valve body, and the filter filters out dust from the atmosphere, and the check ball stops the air from entering the atmosphere, preventing dust from entering during resin plasticization. will not enter the heating cylinder and reduce the quality of the molded product. Further, the check ball can be easily removed from the check valve body and the check valve body can be used as a hopper for purging agent, etc., which is very convenient.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the present invention. Figure 1 is a cross-sectional view of the main parts showing how the check valve main body etc. are installed, and Figure 2 is a cross-sectional view showing how the sub-hopper etc. are installed. It is a diagram. FIG. 3 is a sectional view of a conventional plasticizing device. 1...Nozzle, 2...Heating cylinder, 2a...Resin supply hole, 3...Screw, 4a...Communication hole, 4b
... Branch hole, 5... Hotupa.

Claims (1)

[Scope of utility model registration request] A nozzle 1 is provided at one end, and a resin supply hole 2a is provided at the other end.
In a plasticizing apparatus for resin in an injection molding machine, a screw 3 is inserted into a heating cylinder 2 formed with Hole 4
A branch hole 4b is connected to the branch hole 4b, and a check valve body 9 having a valve seat 9a therein is removably attached to the open end of the branch hole 4b. It contacts the valve seat 9a with its own weight to close the branch hole 4b, and when air pressure or gas pressure is applied to the branch hole 4b side, it separates upward from the valve seat 9a, allowing air and gas to flow freely to the outside. A resin injection molding machine characterized in that a check ball 10 is inserted vertically and freely, and a lid 12 with a filter 11 is detachably attached to the upper end of the check valve main body 9. Plasticizing equipment.