JPH066886Y2 - Mixing device of synthetic resin material for injection molding machine - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention crushes used synthetic resin such as synthetic resin solidified in the runner part of the mold in an injection molding machine into chips by a crusher. The present invention relates to a device for mixing the recycled material crushed into chips into a new pellet material when the recycled material is reused as a molding material.

[Conventional technology]

In injection molding of synthetic resin, since a considerable amount of resin solidifies in the runner part of the mold, in order to save material costs, the synthetic resin solidified in these runner parts is chipped with a crusher. It has been crushed and mixed with new material in pellet form at an appropriate ratio and reused.Therefore, conventionally, a certain amount of new material and recycled material are dropped onto a vibration conveyor, and both are mixed. Although a device was used in which the material is moved by a swinging action while being mixed in a certain direction, this vibrating conveyor type mixing device has the advantage of being able to uniformly mix the new material and the regenerated material. Since a large area is required, the apparatus becomes large in size, and the working environment is deteriorated due to vibration and noise, and the structure is complicated, so that it is expensive.

Therefore, JP-B-62-22333 as a prior art discloses that a new material tank is provided at the upper end of the crusher, and the new material tank and the vicinity of the recycled material discharge port of the crusher are connected by a pipe, By using compressed air to intermittently transfer a fixed amount to the vicinity of the recycled material discharge port of the crusher, the new material and the recycled material can be constantly added to the position near the recycled material discharge port of the crusher. It proposes a device in which these are stored and transferred by compressed air to a hopper of an injection molding machine.

[Problems to be solved by the device]

According to the above-mentioned prior art, since the inside of the crusher is also used as the mixing device, the device can be downsized, and there is an advantage that the working environment can be improved by eliminating noise, vibration, etc. The material is instantaneously transferred to the vicinity of the recycled material discharge port in the crusher by compressed air, and the recycled material accumulates on this new material. The new material and recycled material are separated into two layers in the crusher. Will be accumulated,
There is a problem that the new material and the recycled material cannot be mixed evenly.

An object of the present invention is to make a device capable of homogeneously mixing a new material and a recycled material compact and inexpensive.

[Means for Solving the Problems]

In order to achieve this object, the present invention provides a mixing chamber, which is an open top type and has stirring blades inside, and a receiving chamber, which is also an open top type, adjacent to each other via a weir plate, and the mixing chamber is provided with While facing the supply port of recycled material crushed from used synthetic resin, a new material tank containing new synthetic resin pellets is placed at a position higher than the mixing chamber, and the new material tank A structure in which a new material outlet is opened in the mixing chamber so that the new material is introduced into the mixing chamber according to the rotation of the stirring blades, and the receiving chamber faces a means for taking out the mixed material. I chose

[Function and effect of device]

With this configuration, the new material tank is positioned higher than the mixing chamber, which allows the new material to naturally flow into the mixing chamber, while the new material is
Since it is introduced into the mixing chamber according to the rotation of the stirring blade, when the stirring blade rotates at a constant speed, the new material flows into the mixing chamber by a fixed amount per unit time and is separately supplied into the mixing chamber. The recycled material is agitated with a stirring blade and mixed homogeneously, and the material already in the mixing chamber spills over the barrier plate into the receiving chamber and spills into the receiving chamber as much as it exceeds the ease of the mixing chamber. The used material is intermittently (or continuously) transferred to the hopper of the injection molding machine by an appropriate take-out means.

Thus, the stirring blade not only has the function of simply mixing the new material and the recycled material, but also has the function of taking the new material into the mixing chamber in a fixed amount, so that the new material is supplied into the mixing chamber in a fixed amount. There is no need to install a separate device,
The manufacturing cost can be reduced by simplifying the structure, and since mixing can be done simply by rotating the stirring blade, there is no vibration or noise and it is possible to prevent the deterioration of the working environment and to use new materials. Since the regenerated material is agitated in the mixing chamber, the new material and the regenerated material can be homogeneously mixed without increasing the plane area of the mixing chamber, and the entire apparatus can be made compact.

Further, if the rotation speed of the stirring blade is kept constant, the amount of new material supplied into the mixing chamber per unit time is constant, so for example, the discharge port of the crusher for the used material and the mixing chamber are A simple structure, in which only the synthetic resin extracted from the runner part of the mold is put into the crusher and the recycled material is supplied into the mixing chamber in a fixed amount per unit time. By this, the mixing ratio of the new material and the recycled material can be kept substantially constant. Further, the new material enters the mixing chamber according to the rotation of the stirring blade, and the rotation speed of the stirring blade is changed. As a result, the amount of new material entering the mixing chamber can be adjusted, so that the mixing ratio of the new material and the recycled material can be changed extremely easily.

Therefore, according to the present invention, the mixing device capable of homogeneously mixing the new material and the mixed material and preventing vibration and noise can be made compact and can be manufactured at low cost. In addition, it is possible to keep the mixing ratio of the new material and the recycled material constant and to change the mixing ratio extremely easily.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes an injection molding machine including a hopper 2, a heating cylinder 3 and a mold 4, and reference numeral 5 denotes the mold 4. A crusher for crushing the synthetic resin A taken out from the runner portion into chips is further provided, and reference numeral 6 is for mixing the pelletized new material B and the recycled material C crushed by the crusher 5. The respective mixing devices are shown.

The mixing device 6 includes a box-shaped container 6a, and the container 6a
Inside, a mixing chamber 7 having an open upper surface and a receiving chamber 8 having an open upper surface are formed adjacent to each other via a dam plate 7a. Inside the mixing chamber 7, the dam plate 7a and the dam plate are formed. A rotary shaft 9 extending between 7a and one end 7b on the opposite side is rotatably supported by the rotary shaft 9,
Two stirring blades 10 extending in substantially the same direction as the rotary shaft 9
Is attached via a connecting rod 11 so that the stirring blade 10 rotates along the inner surface of the mixing chamber 7.
0 is configured to be freely driven by the motor 12 with a speed reducer.

As shown in FIG. 5, the stirring blade 10 has a dam plate 7
The new material B and the recycled material C are mixed and transferred toward the dam plate 7a while being twisted at an appropriate angle with respect to the rotation shaft 9 so that the end portion close to a is located rearward in the rotation direction. To configure.

Further, a new material outlet 13 is opened at a portion of the side plate 7c of the mixing chamber 7 which is close to the one end 7b of the mixing chamber 7 and below the upper end of the dam plate 7a, and the new material supply port 13 is provided. Is connected to a supply cylinder 14 extending obliquely upward, and the supply cylinder 14 and a discharge duct 16 of a new material tank 15 provided at a position higher than the mixing chamber 7 are connected via a joint 17, A slit 18 is formed in an upper portion of a connection portion between the supply cylinder 14 and the side plate 7c of the mixing chamber 7, and the slit 18 is formed.
A shutter 19 is vertically slidably inserted therein, and the shutter 19 is fixed to a bracket 20 fixed to the outer surface of the side plate 7c of the mixing chamber 7 by bolts 21 and nuts 22 so that the height of the shutter 19 can be adjusted. The opening area of the material outlet 13 is made adjustable.

Further, a compressed air type cyclone 23 having a downward opening is provided at a portion of the top plate of the container 6a near the one end 7b of the mixing chamber 7, and the cyclone 23 is provided with the crusher 5
Connect the discharge port of via the hose 24 (or pipe),
The synthetic resin A taken out from the runner portion of the mold 4 is crushed into chips by the crusher 5 and then continuously fed into the mixing chamber 7 as the recycled material C.

Then, the tip of a vacuum type conveyor 25 as an example of a means for transferring the mixed material D is faced in the receiving chamber 8, and the other end of the vacuum type conveyor 25 is connected to the hopper 2 of the injection molding machine 1.
While the mixed material D is configured to be intermittently transferred into the hopper 2, an example of a storage amount detecting means (sensor) for the mixed material D is provided on the inner surface of the receiving chamber 8. Is provided with the impeller type switch 26, and the switch 26 and the drive motor 12 of the stirring blade 10 are rotated by the rotation of the impeller of the switch 26 so that the mixed material D is stored in the receiving chamber 8. When the rotation of the impeller is stopped by the charging of the motor, the rotation of the motor 12 is stopped.

In the above configuration, the new material B and the regenerated material C are accumulated in the mixing chamber 7 up to the height of the dam plate 7a, and the new material outlet is filled with the new material B. Exit 1
The new material B does not flow into the mixing chamber 7 from 3 infinitely.

Then, when the stirring blade 10 is rotated so as to move the location of the new material outlet 13 from the bottom to the top, as shown in FIG. A space 27 with a certain volume is created on the rear side in the traveling direction of
The new material B flows into the void 27 created when the stirring blade 10 passes through the new material outlet 13, so that the new material B is supplied at a constant amount per unit time to a portion of the mixing chamber 7 near the one end 7b. On the other hand, the regenerated material C pulverized by the pulverizer 5 is supplied to a portion near the one end 7b in the mixing chamber 7 via the pipe 24 and the cyclone 23, and the regenerated material C and the new material B are mixed with a stirring blade. Weir plate 7a while being mixed at 10.
The mixed material D is spilled from the weir plate 7a into the receiving chamber 8 by an amount exceeding the capacity of the mixing chamber 7, and the mixed material D is shown by a dashed line 28 in FIG. When the receiving chamber 8 is full, the impeller-type switch 26 operates to stop the rotation of the motor 12 and stop the mixing action.

Then, the mixed material D accumulated in the receiving chamber 8 is intermittently transferred to the hopper 2 of the injection molding machine 1 by the vacuum conveyor 25, and the amount of the mixed material D in the receiving chamber 8 is constant. In the following cases, the impeller-type switch 26 is activated to rotate the motor 12, and the new material B and the regenerated material C are mixed, and the cycle is repeated.

In this case, as in the embodiment, the discharge chamber of the crusher 5 is directly connected to the mixing chamber 7 so that only the synthetic resin A extracted from the runner portion of the mold 5 is used as the recycled material B. Then, when the injection molding machine 1 is continuously operating, the amount of synthetic resin A taken out from the runner portion of the mold 4 is also constant per unit time, so that it is supplied into the mixing chamber 7. Since the amount of the recycled material C is also constant per unit time, the mixing ratio of the new material B and the recycled material C can be kept substantially constant.

Further, the mixing ratio of the new material B and the recycled material C is adjusted by changing the rotation speed of the stirring blade 10 or adjusting the shutter 19 up and down to increase or decrease the area of the new material outlet 13, It can be easily performed by adjusting the amount of the new material B entering the mixing chamber 7.

The regenerated material C is fed into the mixing chamber 7 only when the operation of the cyclone 23 and the rotation of the motor 12 are interlocked with each other and the motor 12 is rotated to supply the new material B into the mixing chamber 7. Alternatively, or as shown by the alternate long and short dash line in FIG. 3, a movable shutter 29 of an electromagnetic drive type is provided at the lower end of the cyclone 23 and the shutter 29 is opened only when the motor 12 is rotating. In this way, the mixing ratio of the new material B and the recycled material C can be adjusted more accurately.

Further, the number of the stirring blades 10 is not limited to two, but one or three.
Needless to say, the number of sheets may be one or more, and the shape of the stirring blade 10 may be, for example, the one as shown in FIG. 7, and the mixing in the receiving chamber 8 may be completed. It goes without saying that a photoelectric type sensor or an ultrasonic type sensor may be used as the storage amount detecting means of the material D.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a front view showing the overall layout, FIG. 2 is a vertical sectional front view of a mixing apparatus, and FIG.
FIG. 4 is a sectional view taken along line III-III in FIG. 2, and FIG. 4 is IV- in FIG.
FIG. 5 is a plan view of the mixing chamber, FIG. 6 is a view showing the action, and FIG. 7 is another example of the stirring blade. B: new material, C: recycled material, D: mixed material,
1 ... Injection molding machine, 2 ... Hopper, 5 ... Crusher, 6
…… Mixing device, 7 …… Mixing chamber, 7a …… Weir plate, 7b ……
One end, 7c ... side plate, 8 ... receiving chamber, 9 ... rotating shaft, 1
0 ... Stirring blade, 13 ... New material outlet, 15 ... New material tank, 19 ... Shutter, 23 ... Cyclone as an example of recycled material supply means, 25 ... Example of mixed material transfer means Vacuum conveyor as an example, 26 ... An impeller switch as an example of a means for detecting a mixed material.

Claims (1)

[Scope of utility model registration request] 1. A mixing chamber having an open upper surface and internally provided with a stirring blade and a receiving chamber having the same open upper surface are provided adjacent to each other via a dam plate, and used synthetic resin is placed in the mixing chamber. While facing the supply port of the crushed recycled material, a new material tank containing a new synthetic resin material in the form of pellets is arranged at a position higher than the mixing chamber, and a new material outlet from the new material tank is provided. The mixing chamber is opened so that the new material is introduced into the mixing chamber in accordance with the rotation of the stirring blade, and the receiving chamber faces a means for taking out the mixed material. Mixing device of synthetic resin material for injection molding machine.