JP4021666B2 - Injection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an injection apparatus.
[0002]
[Prior art]
Conventionally, in an injection molding machine, a resin as a molding material heated and melted in a heating cylinder is injected at a high pressure to fill the cavity space of the mold apparatus, and the resin is cooled in the cavity space. It is possible to obtain a molded product by solidifying it.
[0003]
The injection molding machine includes a mold device, a mold clamping device, and an injection device. The mold clamping device includes a fixed platen and a movable platen, and the mold platen of the mold device is moved forward and backward by a mold clamping drive unit. Mold closing, mold clamping and mold opening are performed.
[0004]
On the other hand, the injection device includes a heating cylinder that heats and melts the resin, and an injection nozzle that injects the molten resin, and a screw is rotatably and reciprocally disposed in the heating cylinder. The Then, the resin is injected from the injection nozzle by advancing the screw by a driving unit disposed at the rear end, and the resin is measured by rotating the screw by the driving unit.
[0005]
FIG. 2 is a sectional view of a conventional injection apparatus.
[0006]
In the figure, 11 is a heating cylinder, 12 is a screw arranged to be rotatable in the heating cylinder 11 and can be moved forward and backward (moved in the left and right direction in the figure), and 13 is a front end of the heating cylinder 11 (in the figure). An injection nozzle attached to the left end), 14 is a nozzle port formed in the injection nozzle 13, and 15 is a molding material supply port formed at a predetermined position near the rear end (right end in the figure) of the heating cylinder 11. A resin supply port 17, a resin input portion 17 as a molding material input portion for supplying a resin (not shown) to the heating cylinder 11, and a hopper 16 for storing the resin. Heaters h1 to h3 are disposed on the outer periphery of the heating cylinder 11, and heaters h4 are disposed on the outer periphery of the injection nozzle 13. By energizing the heaters h1 to h4, the resin can be heated and melted. . Note that a plurality of temperature sensors (not shown) are embedded in a predetermined portion of the heating cylinder 11, and temperature control is performed so that the resin has a preset temperature. A metering motor and an injection motor (not shown) are disposed at the rear end of the screw 12.
[0007]
The screw 12 includes a flight part 21 and a screw head 27 disposed at the front end of the flight part 21. The flight portion 21 includes a flight 23 formed in a spiral shape on the outer surface of the screw 12, that is, the outer periphery of the screw body, and a spiral groove 24 is formed by the flight 23. The flight part 21 is compressed in order from the rear (right side in the figure) to the front (left side in the figure), the supply part P1 to which the resin supplied by the resin charging part 17 is supplied, and the supplied resin. Thus, a compression part P2 for melting and a weighing part P3 for measuring the molten resin by a certain amount are formed. The bottom of the groove 24, that is, the outer diameter of the screw body is relatively small in the supply part P1, gradually increased from the rear to the front in the compression part P2, and relatively large in the measuring part P3. Therefore, the gap (gap) between the inner peripheral surface of the heating cylinder 11 and the outer peripheral surface of the screw body is relatively large in the supply unit P1, and gradually decreased from the rear to the front in the compression unit P2. It is made relatively small at P3.
[0008]
By the way, the resin charging part 17 is disposed adjacent to the hopper 16 and the lower end of the hopper 16, and is adjacent to the lower end of the feed screw 18 and the rotary feed screw 18 that supplies a set amount of resin. A cylindrical guide portion 19 that is disposed and guides the resin supplied by the feed screw 18 and a negative pressure forming portion 20 that is disposed adjacent to the lower end of the guide portion 19 are provided. Reference numeral 51 denotes a supply motor.
[0009]
When the screw 12 is rotated in the positive direction by driving the metering motor during the metering process, the resin in the hopper 16 passes through the feed screw 18, the guide unit 19, the negative pressure forming unit 20, and the resin supply port 15. Then, it is supplied to the supply part P1 and moved forward (moved to the left in the figure) in the groove 24. Along with this, the screw 12 is moved backward (moved to the right in the figure), and the resin is stored in front of the screw head 27. The resin in the groove 24 has a pellet shape in the supply part P1, is in a semi-molten state in the compression part P2, and is completely melted in the metering part P3 to become a liquid.
[0010]
When the screw 12 is advanced by driving the injection motor during the injection process, the resin stored in front of the screw head 27 is injected from the injection nozzle 13 and the mold is closed (not shown) The cavity space in the device is filled. At this time, a backflow prevention device 36 including a check ring 37 and a seal ring 38 is disposed around the screw head 27 so that the resin stored in front of the screw head 27 does not flow back.
[0011]
[Problems to be solved by the invention]
However, in the conventional injection device, the molten resin is drawn into a string when the mold is opened, and a string drawing phenomenon occurs, or the resin in the injection nozzle 13 and the heating cylinder 11 is deteriorated, burned, discolored, etc. It will occur.
[0012]
Therefore, the temperature set in the temperature control, that is, the setting is set in order to prevent the yarn drawing phenomenon or the deterioration, burning, discoloration or the like from occurring in the resin in the injection nozzle 13 or the heating cylinder 11. Although it is conceivable to lower the temperature, the speed of solidification varies depending on the resin. Therefore, when using a resin with a low speed of solidification, if the set temperature is lowered, the temperature of the resin in the heating cylinder 11 should be sufficiently high. Not only the quality of the molded product is deteriorated but also the resin in the injection nozzle 13 is solidified.
[0013]
The present invention solves the problems of the conventional injection device and causes a stringing phenomenon, deterioration, burning, discoloration, etc. in the molding material in the injection nozzle, heating cylinder, etc. An object of the present invention is to provide an injection device in which the quality does not deteriorate and the molding material in the injection nozzle does not solidify.
[0014]
[Means for Solving the Problems]
For this purpose, in the injection device of the present invention, a cylinder member, an injection member disposed in the cylinder member so as to be movable back and forth, an injection nozzle attached to the front end of the cylinder member, and an outer periphery of the injection nozzle A heat-conducting member made of a heat-conducting material detachably disposed; and a heater disposed on the outer periphery of the heat-conducting member.
The heat conducting member is divided in the circumferential direction and includes a plurality of divided pieces.
Further, at least one of the divided pieces is made of a heat conducting material having a thermal conductivity different from that of the other divided pieces.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0021]
FIG. 1 is a cross-sectional view of an injection apparatus according to an embodiment of the present invention.
[0022]
In the figure, 11 is a heating cylinder as a cylinder member, 12 is a screw as an injection member disposed so as to be able to rotate and move back and forth (moves in the left-right direction in the figure) in the heating cylinder 11, An injection nozzle attached to the front end (left end in the figure) of the heating cylinder 11, 14 is a nozzle port formed in the injection nozzle 13, and 15 is a predetermined position near the rear end (right end in the figure) of the heating cylinder 11. A resin supply port 17 as a molding material supply port formed on the resin, 17 is a resin input portion as a molding material input portion for supplying a resin (not shown) as a molding material to the heating cylinder 11, and 16 stores the resin. It is a hopper. On the outer periphery of the heating cylinder 11, heaters h1 to h3 are arranged via a plurality of ring-shaped heat conducting members 60 to 63, and on the outer periphery of the injection nozzle 13, a heater h5 is composed of a plurality of ring-shaped heat conducting members 41 to 43. The resin can be heated and melted by energizing the heaters h1 to h3 and h5. In addition, temperature sensors 46 to 48 are embedded in predetermined portions of the heating cylinder 11 and the injection nozzle 13, and temperature control is performed so that the resin has a preset temperature. A metering motor and an injection motor as first and second drive units (not shown) are disposed at the rear end of the screw 12.
[0023]
The screw 12 includes a flight part 21 and a screw head 27 disposed at the front end of the flight part 21. The flight unit 21 includes a flight 23 formed in a spiral shape on the outer peripheral surface of the screw body, and the flight 23 forms a spiral groove 24. The flight part 21 is compressed in order from the rear (right side in the figure) to the front (left side in the figure), the supply part P1 to which the resin supplied by the resin charging part 17 is supplied, and the supplied resin. Thus, a compression part P2 for melting and a weighing part P3 for measuring the molten resin by a certain amount are formed. The outer diameter of the screw body is made relatively small in the supply part P1, gradually increased from the rear to the front in the compression part P2, and made relatively large in the measuring part P3. Therefore, the gap between the inner peripheral surface of the heating cylinder 11 and the outer peripheral surface of the screw body is relatively large in the supply portion P1, gradually decreased from the rear to the front in the compression portion P2, and compared in the measuring portion P3. Made small.
[0024]
By the way, the resin charging part 17 is disposed adjacent to the hopper 16 and the lower end of the hopper 16, and is adjacent to the lower end of the feed screw 18 and the rotary feed screw 18 that supplies a set amount of resin. A cylindrical guide portion 19 that is disposed and guides the resin supplied by the feed screw 18 and a negative pressure forming portion 20 that is disposed adjacent to the lower end of the guide portion 19 are provided. Reference numeral 51 denotes a supply motor as a third drive unit.
[0025]
When the screw 12 is rotated in the positive direction by driving the metering motor during the metering process, the resin in the hopper 16 passes through the feed screw 18, the guide unit 19, the negative pressure forming unit 20, and the resin supply port 15. Then, it is supplied to the supply part P1 and moved forward (moved to the left in the figure) in the groove 24. Along with this, the screw 12 is moved backward (moved to the right in the figure), and the resin is stored in front of the screw head 27. The resin in the groove 24 has a pellet shape in the supply part P1, is in a semi-molten state in the compression part P2, and is completely melted in the metering part P3 to become a liquid.
[0026]
When the screw 12 is advanced by driving the injection motor during the injection process, the resin stored in front of the screw head 27 is injected from the injection nozzle 13 and the mold is closed (not shown) The cavity space in the device is filled. At this time, a backflow prevention device 36 including a check ring 37 and a seal ring 38 is disposed around the screw head 27 so that the resin stored in front of the screw head 27 does not flow back.
[0027]
The heat conducting members 41 to 43 are made of a heat conducting material such as a metal having a high thermal conductivity, ceramics (for example, tungsten carbide), and the like, and are detachably disposed on the outer periphery of the injection nozzle 13. The members 41 to 43 are disposed so as to surround the heat conducting members 41 to 43. And according to the resin used, by replacing at least one of the heat conducting members 41 to 43 with another heat conducting member, the amount of heat transmitted between the heater h5 and the injection nozzle 13 is changed, The speed at which the resin in the injection nozzle 13 solidifies can be adjusted. Therefore, as the heat conducting members 41 to 43, various heat conducting members having different widths, thermal conductivities, and the like are prepared in advance.
[0028]
For example, when a resin having a low solidification rate is used, at least one of the heat conducting members 41 to 43 is replaced with another heat conducting member, and the amount of heat transmitted between the heater h5 and the injection nozzle 13 is changed. More specifically, when the heater h5 is turned off, the heat conducting members 41 to 43 become heat radiating members, and the resin in the injection nozzle 13 can be cooled relatively quickly. In addition, since a plurality of the heat conducting members 41 to 43 are disposed, the heat dissipation area is increased and the heat dissipation is improved.
[0029]
On the other hand, when a resin having a high solidification rate is used, at least one of the heat conducting members 41 to 43 is replaced with another heat conducting member, and the amount of heat transmitted between the heater h5 and the injection nozzle 13 is increased. If it decreases, when the heater h5 is turned off, the speed at which the resin in the injection nozzle 13 is cooled becomes appropriate.
[0030]
Accordingly, the molten resin is not drawn into a string shape when the mold is opened, and the pulling phenomenon does not occur, and the resin in the injection nozzle 13 does not deteriorate, burn, discolor, or the like.
[0031]
Further, it is not necessary to lower the set temperature in the temperature control in order to prevent the stringing phenomenon or the resin in the injection nozzle 13 from being deteriorated, burnt, or discolored. For example, since it is not necessary to lower the set temperature when using a resin having a low solidification speed, the temperature of the resin in the heating cylinder 11 can be sufficiently increased, and the quality of the molded product does not deteriorate. In addition, the resin in the injection nozzle 13 does not solidify.
[0032]
And since the said heater h5 is arrange | positioned over each heat-conducting member 41-43, even when the heat conductivity of at least one of the heat-conducting members 41-43 differs from another heat-conducting member, each heat-conducting member 41-43. Can be equalized. Therefore, the heat distribution in the axial direction of the injection nozzle 13 can be made uniform.
[0033]
The heat conducting members 60 to 63 are made of a heat conducting material such as a metal having a high or low thermal conductivity, ceramics (for example, tungsten carbide), and the like, and are detachably attached to the heating cylinder 11, and include heaters h1 to h1. h3 is arranged over the heat conducting members 60 to 63 and covering the heat conducting members 60 to 63. Then, in accordance with the resin used, the amount of heat transmitted between the heaters h1 to h3 and the heating cylinder 11 is changed by replacing at least one of the heat conducting members 60 to 63 with another heat conducting member. The speed at which the resin in the heating cylinder 11 melts can be adjusted, and the temperature of the melted resin can be adjusted. Therefore, as the heat conducting members 60 to 63, various heat conducting members having different widths, thermal conductivities, and the like are prepared in advance.
[0034]
By the way, when only the heaters h1 to h3 are disposed, the entire temperature of the heating cylinder 11 can be adjusted, but the partial temperature cannot be adjusted. On the other hand, in this Embodiment, since the some heat-conducting members 60-63 are arrange | positioned along the longitudinal direction of the heating cylinder 11, the speed | rate at which resin melts in each area | region of the longitudinal direction of the heating cylinder 11 Or the temperature of the melted resin can be adjusted.
[0035]
By the way, the said heat-conducting members 41-43 and 60-63 can be divided | segmented in the circumferential direction, and can be comprised by several fan-shaped division | segmentation pieces. In that case, at least one of the divided pieces can be formed of a heat conducting material having a thermal conductivity different from that of the other divided pieces. For example, in the compression part P <b> 2 of the heating cylinder 11, there is a melted resin and an unmelted resin, and the melted resin tends to accumulate downward. Therefore, in order to make the molten state of the resin uniform in the circumferential direction of the compression part P2, the lower part of the divided parts of the heat conducting members 60 to 63 in the compression part P2, particularly the lowermost part. The heat conducting material has a lower thermal conductivity than the other divided pieces.
[0036]
When the resin used is changed, the heaters h1 to h3 and h5 are removed by removing a predetermined heat conducting member from the heat conducting members 41 to 43 and 60 to 63 or adding another heat conducting member. The amount of heat transmitted between the injection nozzle 13 or the heating cylinder 11 is changed, and the speed at which the resin in the injection nozzle 13 or the heating cylinder 11 solidifies, the speed at which it melts, the temperature of the melted resin, etc. are adjusted. You can also.
[0037]
In the present embodiment, ring-shaped members are used as the heat conducting members 41 to 43 and 60 to 63, but any shape, for example, a belt-like heat conducting member extending in the axial direction may be used. Moreover, the heat conducting members 41 to 43 can be changed to ones having different thermal conductivities as the resin is changed.
[0038]
By disposing a heat conducting member between the heaters h1 to h3 and the heating cylinder 11, it is possible to prevent the resin in the heating cylinder 11 from being deteriorated, burned, discolored, or the like.
[0039]
In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.
[0040]
【The invention's effect】
As described above in detail, according to the present invention, in the injection device, the cylinder member, the injection member disposed in the cylinder member so as to be movable back and forth, and the injection nozzle attached to the front end of the cylinder member And a heat conducting member made of a heat conducting material detachably disposed on the outer periphery of the injection nozzle, and a heater disposed on the outer periphery of the heat conducting member.
The heat conducting member is divided in the circumferential direction and includes a plurality of divided pieces.
Further, at least one of the divided pieces is made of a heat conducting material having a thermal conductivity different from that of the other divided pieces.
[0041]
In this case, the amount of heat transferred between the heater and the injection nozzle is changed by changing the heat conducting member in accordance with the molding material to be used, so that the molding material in the injection nozzle is melted at a speed. The temperature of the obtained resin can be adjusted.
[0042]
Therefore, the molding material in a molten state is not drawn into a string when the mold is opened, and the yarn drawing phenomenon does not occur, and the molding material in the injection nozzle does not deteriorate, burn, discolor, or the like.
[0043]
In addition, it is not necessary to lower the set temperature in temperature control in order to prevent the occurrence of stringing phenomenon or deterioration, burning, discoloration, etc. in the molding material in the injection nozzle. The temperature of the molding material can be made sufficiently high, so that the quality of the molded product does not deteriorate, and the molding material in the injection nozzle does not solidify.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an injection apparatus according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a conventional injection device.
[Explanation of symbols]
11 Heating cylinder 12 Screw 13 Injection nozzles 41 to 43 Heat conducting member h5 Heater

Claims (5)

(A) a cylinder member;
(B) an injection member disposed in the cylinder member so as to freely advance and retract;
(C) an injection nozzle attached to the front end of the cylinder member;
(D) a heat conducting member made of a heat conducting material detachably disposed on the outer periphery of the injection nozzle;
(E) having a heater disposed on the outer periphery of the heat conducting member ;
(F) The heat conducting member is divided in a circumferential direction and includes a plurality of divided pieces,
(G) An injection device characterized in that at least one of the divided pieces is made of a heat conducting material having a thermal conductivity different from that of the other divided pieces . (A) a cylinder member;
(B) an injection member disposed in the cylinder member so as to freely advance and retract;
(C) an injection nozzle attached to the front end of the cylinder member;
(D) a heat conducting member made of a heat conducting material detachably disposed on the outer periphery of the cylinder member;
(E) having a heater disposed on the outer periphery of the heat conducting member ;
(F) The heat conducting member is divided in a circumferential direction and includes a plurality of divided pieces,
(G) An injection device characterized in that at least one of the divided pieces is made of a heat conducting material having a thermal conductivity different from that of the other divided pieces .   The injection device according to claim 1, wherein a plurality of the heat conducting members are provided. The injection device according to claim 3, wherein the heater is disposed over each heat conducting member . One of the previous SL respective segments is disposed below, the injection device according to claim 1 or 2 consisting of a low thermal conductivity heat conducting material than the other divided piece.

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