JP2007152587A - Resin cooling mechanism of injection molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the resin cooling mechanism of an injection molding machine which can curtail a molding cycle time while appropriately controlling the occurrence of stringiness. <P>SOLUTION: The tip part of a medium circulation part 14 is penetration-arranged in a resin injection opening 12 side part in the resin passage 13 of an injection nozzle 11. A supply control part 18 supplies cooling air to a medium passage in the medium circulation part 14 and controls the supply of the cooling air. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a resin cooling mechanism in an injection molding machine.

  Generally, a molding cycle by an injection molding machine is a process of heating and melting a molding material (resin chip) in a heating cylinder (injection nozzle) of the injection molding machine (heating and melting process), and injecting the heated and melted resin from the nozzle. One cycle includes a step of filling the mold (filling step) and a step of cooling and solidifying the filled resin to release the mold (cooling step).

  Conventionally, it has been desired to improve the productivity of molded products by shortening the molding cycle time. However, it is difficult to simply shorten the molding cycle time. For example, when the cooling process time is shortened, the resin is not suitably cut at the resin injection port portion of the injection nozzle when the molded product is released. There is a possibility that a stringing phenomenon in which the resin yarn remains in the molded product may occur. When such a yarn drawing phenomenon occurs, the yarn remains in the mold, and the yarn is mixed into a molded product to be molded in the next cycle, so that the molded product becomes a defective product and yield decreases. There is a fear. For this reason, it is necessary to suppress the occurrence of such a stringing phenomenon.

Therefore, conventionally, for example, a yarn drawing prevention technique described in Patent Document 1 and Patent Document 2 has been proposed.
Specifically, in Patent Document 1, the temperature of the resin injection port portion of the injection nozzle is lowered by jetting a cooling gas toward the outer surface of the injection nozzle, thereby favoring the resin at the time of mold release. It is designed to promote cutting. For this reason, even if the cooling time is shortened compared to before that, the yarn drawing phenomenon is suppressed.

  Moreover, in patent document 2, the inhibition member (piece | piece member) which blocks | prevents that molten resin flows into the center of this resin flow path is arrange | positioned in the resin injection-portion part in the resin flow path in an injection nozzle. Usually, the solidification of the resin starts from the outer surface portion, and the central portion where the temperature is difficult to decrease is solidified last. For this reason, by disposing the blocking member at the resin injection port part, it is difficult for the molten resin to flow into the central part of the resin flow path at the resin injection port, so that the solidification of the resin is promoted and the cooling time is shortened. Also, the stringing phenomenon is suppressed.

Therefore, these conventional techniques can shorten the molding cycle time.
Japanese Patent Laid-Open No. 2003-211513 JP 2001-246642 A

However, in recent years, there has been a demand for further shortening of the molding cycle time in order to further improve productivity.
However, even with the conventional technology, if the cooling time is further shortened to further shorten the molding cycle time, the yarn drawing phenomenon occurs and the yield deteriorates. It was practically difficult to shorten the molding cycle time.

  The present invention has been made in view of such circumstances, and an object thereof is a resin cooling mechanism in an injection molding machine that can further reduce the molding cycle time while suitably suppressing the occurrence of the yarn drawing phenomenon. Is to provide.

  In order to solve the above-described problems, in the invention according to claim 1, a pipe-shaped medium circulation portion disposed at a resin injection port side portion in a resin flow path provided in an injection nozzle of an injection molding machine. And a medium supply control means for controlling the supply of the cooling medium while supplying the cooling medium into the medium circulation part.

  According to the above configuration, since the medium flow part is provided in the resin flow path in the injection nozzle, the resin itself flowing through the resin flow path is cooled by the cooling medium by flowing the cooling medium in the medium flow part. Will be. In addition, since the medium flow part is disposed at the resin injection port side portion, the resin located near the resin injection port is directly cooled. Therefore, since the solidification time of the resin is shortened, even if the time required for the process of cooling and releasing the molded product is shortened, the stringing phenomenon hardly occurs in the molded product. In other words, the molding cycle time can be shortened while suppressing the yarn drawing phenomenon.

  According to a second aspect of the present invention, in the resin cooling mechanism in the injection molding machine according to the first aspect, the medium flow portion intersects the flow direction of the resin at a resin injection port side portion of the injection nozzle. The gist is that it is arranged through.

  According to the above configuration, since the medium flow part is disposed so as to penetrate in the direction intersecting the resin flow direction, the resin flowing through the resin flow path always comes into contact with the medium flow part. Therefore, when the cooling medium is supplied to the medium circulation part, the resin in contact with the medium circulation part is reliably cooled by the cooling medium.

  According to a third aspect of the present invention, in the resin cooling mechanism in the injection molding machine according to the first or second aspect, the medium flow portion is disposed so as to pass through a central portion of the resin flow path. The gist.

  According to the said structure, when a cooling medium is distribute | circulated to a medium distribution part, it cools preferentially from the center site | part of resin. Usually, the solidification of the resin starts from the outer surface portion, and the central portion where the temperature is difficult to decrease is solidified last. For this reason, by preferentially cooling from the central part of the resin, the solidification of the resin can be promoted, and the solidification time can be shortened.

  According to a fourth aspect of the present invention, in the resin cooling mechanism in the injection molding machine according to any one of the first to third aspects, the medium supply control means includes a resin material, an injection nozzle heating temperature, a resin injection The gist is to control the supply start timing and supply stop timing of the cooling medium using at least one of the outlet diameter, the sprue diameter, and the size of the resin molded product as a displacement parameter.

  According to the above configuration, the supply start timing and the supply stop timing of the cooling medium are set to at least one of the resin material, the heating temperature of the injection nozzle, the diameter of the resin injection port, the diameter of the sprue, and the size of the resin molded product. Therefore, the resin is cooled at an optimal cooling timing.

  According to a fifth aspect of the present invention, in the resin cooling mechanism in the injection molding machine according to any one of the first to fourth aspects of the present invention, the medium supply control means adds the cooling medium to the heating medium and heats the medium circulation portion. The gist is to supply the media and control the supply of the media.

  According to the said structure, not only a cooling medium but a heating medium is distribute | circulated in the medium distribution part. For this reason, for example, when the heating medium is circulated in the medium flow portion when the injection nozzle is heated to melt the resin in the resin flow path, the melting of the resin can be promoted, and the heating time of the resin is reduced. Can also be shortened. Therefore, it is possible to further shorten the molding cycle time while suppressing the yarn drawing phenomenon.

  As described above in detail, according to the present invention, it is possible to provide a resin cooling mechanism in an injection molding machine capable of further reducing the molding cycle time while suitably suppressing the occurrence of the yarn drawing phenomenon. it can.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS.
As shown in FIG. 1, an injection mold 1 includes a fixed mold 2 attached to a fixed platen (not shown), and a movable mold 3 that can be attached to and detached from the fixed mold 2 by being attached to a movable platen (not shown). And is composed of.

  The fixed mold 2 includes a fixed mold plate 4 attached to a fixed platen, a sprue bush 5 embedded in the fixed mold plate 4 and in contact with the movable mold 3, and the sprue bush 5 connected to the fixed mold plate 4. And a locating ring 6 held therein. The sprue bush 5 is provided with a recess 7, and the locate ring 6 is provided with a through-hole 8 communicating with the recess 7. In the innermost part of the recess 7, a sprue 9 penetrating to the movable mold 3 side is provided. Further, a cavity 10 communicating with the spru 9 is recessed on the side surface of the fixed mold in the movable mold 3. The sprue 9 is set so that the diameter gradually increases toward the movable mold 3 side. In the recess 7, the tip portion of the injection nozzle 11 of the injection molding machine is accommodated in a state of passing through the through hole 8. Specifically, in the injection nozzle 11, there are provided a resin injection port 12 penetrating the leading edge and a resin flow path 13 communicating with the resin injection port 12. The injection nozzle 11 is housed in the recess 7 so that the resin injection port 12 matches the sprue. The injection nozzle 11 heats and melts the resin material supplied into the resin flow path 13 by a heating mechanism (not shown), and discharges the heat-melted molten resin from the resin injection port 12 to the outside. For this reason, the molten resin flowing through the resin flow path 13 is supplied from the resin injection port 12 into the cavity 10 through the sprue 9.

  By the way, a pipe-shaped medium circulation portion 14 is disposed through the tip portion of the injection nozzle 11 (near the end portion on the resin injection port 12 side). As shown in FIG. 2A, the medium flow part 14 passes through the center O of the resin flow path 13 from the direction orthogonal to the flow direction of the resin flowing through the resin flow path 13 at the tip portion of the injection nozzle 11. The tip 14 a protrudes outside the injection nozzle 11. Further, as shown in FIG. 2B, the medium circulation part 14 is formed in a cross section of a perfect circle, and a medium flow path 14b is provided therein. And the base end side of the medium circulation part 14 is connected to the pump 15 which is a medium supply source. In the present embodiment, the pump 15 supplies room temperature air as a cooling medium to the medium flow path 14b.

  A control valve 16 for controlling the flow rate of the cooling air flowing through the medium flow path 14b is disposed in the vicinity of the pump 15 in the medium flow portion 14, and in the vicinity of the injection nozzle 11 in the medium flow portion 14, A temperature sensor 17 for detecting the temperature of the cooling air flowing through the medium flow path 14b is provided. The control valve 16 and the temperature sensor 17 are each electrically connected to a supply control unit 18 as medium supply control means. The control valve 16 controls the flow amount of the cooling medium flowing through the medium flow path 14 b based on the flow control signal input from the supply control unit 18. In the present embodiment, the opening degree of the control valve 16 is configured to be linearly changeable by the supply control unit 18.

  For this reason, the flow rate of the cooling medium (cooling air) supplied from the pump 15 is controlled by the control valve 16, and flows through the medium flow path 14b and is discharged to the outside from the tip end 14a.

  The supply control unit 18 is configured by a computer unit including a CPU, ROM, RAM, and the like (not shown), and is based on an input signal from the injection molding machine and a detection signal from the temperature sensor 17. 16 drive is controlled. For this reason, the supply control unit 18 can perform supply control of the cooling air in synchronization with the injection molding machine.

Thus, the medium flow unit 14, the pump 15, the control valve 16, the temperature sensor 17, and the supply control unit 18 constitute a temperature adjustment mechanism in the injection molding machine.
Next, a specific operation example of the temperature adjustment mechanism configured as described above will be described with reference to the sequence chart shown in FIG. 3 and the flowchart shown in FIG.

  As shown in FIG. 3, the molding process by the injection molding machine is performed according to the following procedure. That is, first, in step S1, a heating and melting step is performed in which the resin material (resin chip) supplied into the resin flow path 13 of the injection nozzle 11 is heated and melted by a heating mechanism. Thereafter, in step S2, a filling step of injecting the molten resin into the sprue 9 from the resin injection port 12 of the injection nozzle 11 and filling the cavity 10 is performed. Then, after the cooling process for cooling and solidifying the resin is performed in step S3, a mold releasing process is performed in which the movable mold 3 is released from the fixed mold 2 and the resin molded product is taken out from the cavity 10 in step S4. Is called. That is, in the molding cycle by the injection molding machine, “heating and melting step → filling step → cooling step → mold release step” is one cycle.

  As shown in FIG. 4, in step S <b> 11, based on the input signal from the injection molding machine, the supply control unit 18 performs each process in the molding cycle, resin material information indicating the resin material, and heating the injection nozzle 11. Molding information such as melting temperature information indicating temperature, injection port information indicating the diameter of the resin injection port 12, molded product information indicating the size of the resin molded product, the diameter and length of the sprue 9, and the like are acquired.

  Next, in step S12, the supply control unit 18 determines whether or not it is a cooling start time based on the molding information of the injection molding machine acquired in step S11. In this embodiment, the supply control unit 18 uses at least one of the various pieces of molding information as a displacement parameter, and uses a cooling start timing (cooling air supply start timing) and a cooling end timing (cooling air supply stop timing). ) Is calculated. Incidentally, here, a specific example will be given of a case where the molding cycle is set as the cooling start time when the filling process is almost finished and the end time of the mold release process is set as the cooling end time. In step S12, when the supply control unit 18 determines that it is not the cooling start time, the process is temporarily ended. In contrast, when the supply control unit 18 determines that it is the cooling start time, it performs the cooling process shown in steps S13 to S17.

  That is, in step S13, the supply control unit 18 drives the control valve 16 from the fully closed state to the fully open state by outputting a flow control signal to the control valve 16 and performing control to open the control valve 16. Cooling air (normal temperature air) is circulated through the medium flow path 14b of the medium distribution part 14. For this reason, the cooling air is discharged to the outside from the tip 14 a after flowing through the resin flow path 13 of the injection nozzle 11. As a result, the molten resin flowing through the resin injection port 12 of the injection nozzle 11 and the resin flow path 13 is directly cooled by the cooling air, and the solidification rate of the resin is increased.

  Next, in step S <b> 14, the supply control unit 18 determines whether or not the temperature of the cooling air is an optimum temperature (normal temperature) for cooling based on the detection signal from the temperature sensor 17. As a result, when it is determined that the temperature of the cooling air is not the optimum temperature, the supply controller 18 adjusts the temperature of the cooling air by controlling the opening of the control valve 16 in step S15.

  Specifically, the supply control unit 18 reduces the opening degree of the control valve 16 when the temperature of the cooling air is lower than the optimum temperature, and controls the control valve 16 when the temperature of the cooling air is higher than the optimum temperature. Extend the opening (only if not fully open). Thereby, the temperature of the cooling air is adjusted to the optimum temperature.

  Then, when the processing in step S15 is completed, or when it is determined in step S14 that the cooling air has the optimum temperature, the supply control unit 18 determines whether or not the mold release process by the injection molding machine is completed in step S16. Is determined based on an input signal from the injection molding machine. As a result, when it is determined that the release process has not ended, the supply control unit 18 proceeds to the process of step S14 again, and when it is determined that the release process has ended, the control valve 18 in step S17. The injection of cooling air to the injection nozzle 11 is stopped by controlling 16 from the open state to the fully closed state, and the process here is temporarily terminated.

  Therefore, by performing such a cooling process, the solidification rate of the resin from near the end of the filling process to the completion of the mold release process is increased, and as a result, the time required for the cooling process is shortened. Moreover, at the time of mold release, the stringing phenomenon hardly occurs in the molded product, and the stringing resin is preferably suppressed from remaining in the cavity 10 in the next molding cycle.

Therefore, according to the present embodiment, the following effects can be obtained.
(1) The medium flow part 14 is disposed in the resin flow path 13 in the injection nozzle 11, and the cooling medium (cooling air) is circulated in the medium flow path 14 b of the medium flow part 14. The resin itself flowing through the resin flow path 13 is directly cooled by the cooling air. In addition, since the medium flow part 14 is disposed at the resin injection port 12 side portion of the injection nozzle 11, the resin located near the resin injection port 12 is directly cooled. Therefore, since the cooling time of the resin is shortened by such cooling air, even if the time required for the process of cooling and releasing the molded product is shortened, the stringing phenomenon hardly occurs in the molded product. In other words, the molding cycle time can be shortened while suppressing the yarn drawing phenomenon.

  (2) Since the medium circulation part 14 is disposed through the resin flow direction intersecting the resin flow direction, the resin flowing through the resin flow path 13 always comes into contact with the medium flow part 14. Therefore, when the cooling air is supplied to the medium circulation part 14, the resin in contact with the medium circulation part 14 can be reliably cooled by the cooling air.

  (3) Since the medium circulation part 14 is arranged so as to pass through the central part of the resin flow path 13 (the place of the center O shown in FIG. 2A), the medium circulation part 14 is made to circulate cooling air. In this case, the resin flowing in the resin flow path 13 is preferentially cooled from the central portion. Usually, the solidification of the resin starts from the outer surface portion, and the central portion where the temperature is difficult to decrease is solidified last. For this reason, by preferentially cooling from the central part of the resin, the solidification of the resin can be promoted, and the solidification time can be shortened.

  (4) The cooling air supply start timing and supply stop timing are changed based on at least one of the material of the resin, the heating temperature of the injection nozzle, the diameter of the resin injection port, and the size of the resin molded product. Since it is controlled, the resin can be cooled at an optimal cooling timing.

  (5) The medium distribution unit 14 is disposed in the injection nozzle 11 and is not disposed in the fixed mold 2 or the like. For this reason, in arranging the temperature adjustment mechanism of the present embodiment, it is possible to cope with only the change to the injection nozzle 11, it is not necessary to change the fixed mold 2 or the like, and the temperature without requiring a large-scale change. An adjustment mechanism can be provided.

  (6) The temperature of the cooling air is detected by the temperature sensor 17, and the supply control unit 18 controls the control valve 16 based on the detection result to control the cooling air flow rate to be optimum. For this reason, the cooling control using the medium can be performed with high accuracy.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. Here, the points different from the first embodiment will be mainly described, and common points will be simply denoted by the same member numbers, and the description thereof will be omitted.

This embodiment is different from the first embodiment in that the temperature adjustment mechanism has a heating mechanism.
Specifically, as shown in FIG. 5, the medium circulation part 14 includes a first flow path 21 that is disposed through the injection nozzle 11 and a second flow path 22 that is formed so as to branch from the first flow path 21. And a third flow path 23. One end of the second flow path 22 and the third flow path 23 is connected to the proximal end portion of the first flow path 21, and the other end is connected to the pump 15.

  A first control valve 24 is disposed in the second flow path 22, and a second control valve 25 is disposed in the third flow path 23. These control valves 24 and 25 are individually electrically connected to the supply control unit 18 and control the flow rate of the medium based on a flow control signal input from the supply control unit 18. In the present embodiment, the opening degree of each control valve 24, 25 is configured to be linearly variable by the supply control unit 18.

  The first flow path 21 is provided with the temperature sensor (referred to herein as a “first temperature sensor” for convenience) 17, and the first control valve 24 and the first flow path 21 in the second flow path 22 are arranged. A second temperature sensor 26 is disposed between the second control valve 25 and the first flow path 21 in the third flow path 23. These temperature sensors 17, 26, and 27 are individually electrically connected to the supply control unit 18.

  Furthermore, between the second control valve 25 and the pump 15 in the third flow path 23, a temperature adjusting device 28 for heating the medium flowing through the third flow path 23 to a predetermined temperature (for example, 225 ° C.) is disposed. Has been. The temperature adjusting device 28 is electrically connected to the supply control unit 18 and controls the temperature based on a temperature control signal input from the supply control unit 18.

  For this reason, the flow rate of the air supplied from the pump 15 to the second flow path 22 is controlled by the first control valve 24, and the air flows from the second flow path 22 to the first flow path 21. On the other hand, the temperature of the air supplied from the pump 15 to the third flow path 23 is adjusted by the temperature adjusting device 28, and the flow rate is controlled by the second control valve 25. It will flow to one flow path 21. For this reason, air flowing from the second flow path 22 to the first flow path 21 functions as a cooling medium, and air flowing from the third flow path 23 to the first flow path 21 functions as a heating medium. When air corresponding to each of the second flow path 22 and the third flow path 23 is circulated, the air flows through the first flow path 21 in a mixed state.

  Thus, in the present embodiment, the medium circulation part 14 having the first to third flow paths 21 to 23, the pump 15, the first to third temperature sensors 17, 26, 27, the first and first The two control valves 24 and 25 and the supply control unit 18 constitute a temperature adjustment mechanism in the injection molding machine.

Next, a specific operation example of the temperature adjustment mechanism configured as described above will be described with reference to a flowchart shown in FIG.
That is, as shown in the figure, in step S21, the supply control unit 18 acquires molding information based on the input signal from the injection molding machine, similarly to step S11 shown in FIG. Then, the supply control unit 18 obtains the optimum temperature of the heating medium (heating air) based on such molding information, and outputs a temperature control signal to the temperature adjusting device 28 so as to reach the optimum temperature.

  Next, in step S22, the supply control unit 18 determines whether it is the heating start time based on the molding information of the injection molding machine acquired in step S21. In the present embodiment, the supply control unit 18 uses the heating start timing (heating air supply start timing) using at least one of the various pieces of molding information as a displacement parameter, similarly to the cooling start timing and cooling end timing. ) And heating end timing (heating air supply stop timing) are calculated. Incidentally, here, a case where the start time of the heating and melting step in the molding cycle is set as the heating start time and the end time of the heating and melting step is set as the heating end time will be given as a specific example. In step S22, when the supply control unit 18 determines that it is the heating start time, it performs the heating process shown in steps S23 to S27.

  That is, first, in step S23, the supply control unit 18 outputs a flow control signal to the second control valve 25 to perform open control of the second control valve 25, thereby closing the second control valve 25. To the fully open state, and the heated air is circulated through the third flow path 23. For this reason, the heated air flows from the third flow path 23 to the first flow path 21, and the heating of the resin in the resin flow path 13 of the injection nozzle 11 is promoted to increase the melting rate of the resin. The time required is reduced.

  In step S <b> 24, the supply control unit 18 determines whether the temperature of the medium (heated air) is the optimum temperature based on detection signals from the first temperature sensor 17 and the third temperature sensor 27. As a result, when it is determined that the temperature of the heated air is not the optimum temperature, the supply control unit 18 outputs a temperature control signal to the temperature adjusting device 28 in step S25, and the control valves 24, 25 The temperature of the heated air is adjusted by controlling the opening degree.

  Specifically, when the temperature of the heated air is lower than the optimum temperature, the supply control unit 18 increases the heating temperature of the heated air by the temperature adjustment device 28 and expands the opening of the second control valve 25 ( Only if not fully open). As a result, the temperature of the heated air rises and is adjusted to the optimum temperature.

  On the other hand, when the temperature of the heated air is higher than the optimum temperature, the supply control unit 18 lowers the heating temperature of the heated air by the temperature adjustment device 28 and restricts the opening of the second control valve 25, Further, the first control valve 24 is controlled to open, and the cooling medium (cooling air) is circulated through the second flow path 22. Thereby, heating air and cooling air are mixed in the first flow path 21, and the temperature of the medium flowing through the first flow path 21 is lowered and adjusted to the optimum temperature.

  When the processing in step S25 is completed, or when it is determined in step S24 that the medium temperature is the optimum temperature, the supply control unit 18 determines whether the heating and melting process by the injection molding machine is completed in step S26. Determine whether. As a result, when it is determined that the heating and melting process has not ended, the supply control unit 18 proceeds to the process of step S24 again. When it is determined that the heating and melting process has ended, each control is performed in step S27. The valves 24 and 25 are controlled from the open state to the fully closed state to stop the medium injection to the injection nozzle 11, and the process here is temporarily ended.

Therefore, by performing such heat treatment, the time required for the resin heating and melting step is shortened, and the molding cycle time can be shortened.
On the other hand, if the supply control unit 18 determines in step S22 that the heating start time is not reached, the process proceeds to step S28. In step S28, the supply control unit 18 determines whether or not it is a cooling start time. In this embodiment as well, a specific example is given of a case where the molding cycle is set as the cooling start time when the filling process is nearing the end, and the end time of the mold release process is set as the cooling end time. In step S28, when the supply control unit 18 determines that it is not the cooling start time, it determines that it is neither the heating start time nor the cooling start time, and ends the processing here.

  On the other hand, the supply control unit 18 performs the cooling process shown in steps S29 to S33 when it is determined that it is the cooling start time. In addition, the process of step S29-S33 is equal to the process to step S13-S17 in the said embodiment, and has changed the control valve 16 in the said embodiment to the 1st control valve 24 only. Therefore, the detailed description of the processes in steps S29 to S33 is omitted here.

Therefore, according to this embodiment, in addition to the effects described in the above (1) to (6) in the first embodiment, the following effects can be obtained.
(7) Not only cooling air but also heated air is circulated through the first flow path 21 of the medium flow portion 14 disposed through the resin flow path 13 of the injection nozzle 11. The heated air is circulated in a heating and melting step in which the injection nozzle 11 is heated to melt the resin in the resin flow path 13. For this reason, melting of the resin flowing in the resin flow path 13 can be promoted by the heated air, and not only the time required for the cooling process but also the time required for the heating and melting process can be shortened. Therefore, it is possible to further shorten the molding cycle time while suppressing the stringing phenomenon of the molded product.

  Moreover, since both the cooling medium and the heating medium are composed of fluid (air), the cooling structure and the heating structure can be the same type. For example, cooling is performed using the cooling medium, and the heater Compared to the case where the resin is heated by using, for example, the temperature adjustment mechanism can also be configured with a simple structure.

  (8) Cooling air and heated air are supplied from separate medium flow paths (second flow path 22 and third flow path 23), and these media can be mixed in the first flow path 21. For this reason, the temperature of the medium which distribute | circulates the inside of the resin flow path 13 can be freely adjusted by making it not mix cooling air and heating air. Further, the temperature of the heated air can be quickly adjusted as compared with the case where only the temperature of the heated air is adjusted by the temperature adjusting device 28.

  (9) The opening degree of the first control valve 24 and the second control valve 25 is linearly controlled by the supply control unit 18. In other words, the supply amount of the cooling air and the heating air can be gradually changed by the supply control unit 18. For this reason, when cooling and heating the injection nozzle 11 and the resin, it is possible to set an optimum supply amount of each medium. In particular, when the temperature of the medium is adjusted by mixing the cooling medium and the heating medium, the temperature of the mixed medium can be easily finely adjusted.

  (10) Similarly to the cooling air, at the supply start timing and supply stop timing of the heated air, at least one of the resin material, the heating temperature of the injection nozzle, the diameter of the resin injection port, and the size of the resin molded product Therefore, the resin can be heated at an optimal heating timing.

In addition, you may change embodiment of this invention as follows.
-The cross-sectional shape of the part arrange | positioned in the resin flow path 13 at least in the medium distribution | circulation part 14 is not restricted to the perfect circle shape shown in FIG.2 (b), You may change into various shapes. For example, as shown in FIG. 7A, the cross-sectional shape may be an elliptical shape. In this case, since it is difficult to hinder the flow of the resin and the contact area with the resin is increased, it is preferable that the long axis is arranged in parallel with the resin flow direction as shown in FIG. Further, the cross-sectional shape may be a teardrop shape as shown in FIG. 7B, a rhombus shape as shown in FIG. 7C, or a triangle shape as shown in FIG. 7D. Good. When the cross-sectional shape is a cylindrical shape, the medium flow portion 14 can be easily formed, and when the cross-sectional shape is any other shape, the flow of the resin from the resin flow path 13 to the resin injection port 12 is hardly hindered. Or the contact area with the resin can be increased to enable the resin to be cooled (heated) more effectively.

  The medium circulation part 14 does not necessarily have to be disposed so as to pass through the center O of the resin flow path 13 (see FIG. 2A), and is disposed so as to pass through a place other than the center O. May be. That is, the medium distribution part 14 is configured by, for example, two parallel members that do not pass through the center O as shown in FIG. 8A, or the resin flow path 13 as shown in FIG. 8B. Or an annular member extending along the inner peripheral surface of the injection nozzle 11 to be formed.

  For example, as shown in FIGS. 9A and 9B, a heat insulating bush 31 made of a heat insulating material may be interposed between the injection nozzle 11 and the medium circulation portion 14. In this way, the thermal influence between the injection nozzle 11 and the medium circulation part 14 can be reduced, and temperature management with higher accuracy becomes possible.

  In each of the above embodiments, the cooling medium and the heating medium are constituted by air, and these media are discharged to the outside from the front end 14a of the medium circulation part 14. However, for example, the medium may be recirculated to the pump 15 again. In this way, liquids such as water and environmental pollutants such as chlorofluorocarbon can be easily used as the cooling medium and the heating medium.

  In each of the above embodiments, the cooling start timing and the cooling end timing (including the heating start timing and the heating end timing in the second embodiment) of the injection nozzle 11 by the supply control unit 18 are obtained from the injection molding machine. The supply control unit 18 determines the information based on the information. However, these start time and end time may be fixed at preset timings.

  The opening of the control valve 16 in the first embodiment and the first and second control valves 24 and 25 in the second embodiment are not necessarily linearly controllable. It may change in a binary manner depending on the state. In this way, the control of each control valve 16, 24, 25 by the supply control unit 18 can be simplified.

The temperature of the cooling air is not limited to normal temperature, and may be adjusted to a temperature adjusted by the temperature adjusting device 28 (for example, a temperature equal to or lower than normal temperature).
In the second embodiment, the heating medium is not limited to being heated by the dedicated temperature control device 28, and the third flow path 23 is disposed in the vicinity of the heating mechanism of the injection nozzle 11, for example. It may be heated using the temperature of the mechanism.

  In the second embodiment, the medium flow unit 14 includes the second flow path 22 through which cooling air flows, the third flow path 23 through which heated air flows, and the first flow path where the flow paths 22 and 23 merge. 21. That is, the medium circulation part 14 is configured to include a flow path through which cooling air and heated air individually circulate. However, the medium distribution unit 14 is not limited to such a configuration, and may include, for example, only the first flow path 21 and supply cooling air and heated air to the first flow path 21.

Further, the first flow path 21 may be omitted, and the second flow path 22 and the third flow path 23 may be individually arranged through the injection nozzle 11.
-The temperature sensors 17, 26, 27 may be omitted. In this case, the configuration of the temperature adjustment mechanism can be simplified, and the supply control unit 18 does not perform temperature adjustment based on detection signals from the corresponding temperature sensors 17, 26, 27. The processing burden on the supply control unit 18 can be reduced.

Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the embodiment described above are listed below.
(1) In the resin cooling mechanism in the injection molding machine according to any one of claims 1 to 5, a heat insulating bush is interposed between the injection nozzle and the medium flow part.

(2) In the resin cooling mechanism in the injection molding machine according to any one of claims 1 to 5 and (1), a fluid is used as the cooling medium.
(3) In the technical idea described in (2) above, the cooling medium is air.

  (4) A heat-melting process in which a resin material is heated and melted in an injection nozzle of an injection molding machine, a filling process in which the heat-melted resin is injected from the injection nozzle and filled into a molding die, and the filled resin A method for producing a resin molded product that is molded through a cooling step of cooling and solidifying and releasing, wherein at least in each of the steps, a pipe-shaped medium is disposed in an injection nozzle. A method for producing a resin molded product, comprising: circulating a cooling medium in a section to cool a resin located in the vicinity of the medium circulation section.

  (5) In the technical idea described in (4) above, based on at least one of the resin material, the heating temperature of the injection nozzle, the diameter of the resin injection port, the diameter of the sprue, and the size of the resin molded product. The supply start timing and supply stop timing of the cooling medium are changed.

The figure which shows schematically the temperature control mechanism of the injection molding machine of 1st Embodiment of this invention. (A) is the sectional view on the AA line of FIG. 1, (b) is the sectional view on the BB line of (a). The sequence chart which shows the molding cycle in the injection molding machine of the embodiment. The flowchart which shows the temperature control of the embodiment. The figure which shows schematically the temperature control mechanism of the injection molding machine of 2nd Embodiment of this invention. The flowchart which shows the temperature control of the embodiment. (A)-(d) is sectional drawing which shows roughly the example of a change of the cross-sectional shape of a medium distribution part. (A), (b) is sectional drawing which shows roughly the example of a change of the arrangement position of the medium distribution part with respect to the injection nozzle. (A) is a figure which shows the structure of the injection | spray nozzle and medium distribution part of other embodiment roughly, (b) is an arrow figure from the arrow F direction of (a).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 9 ... Sprue, 11 ... Injection nozzle, 12 ... Resin injection port, 13 ... Resin flow path, 14 ... Medium flow part, 14b ... Medium flow path, 17 ... Control valve, 18 ... Supply control part as medium supply control means, DESCRIPTION OF SYMBOLS 21 ... 1st flow path, 22 ... 2nd flow path, 23 ... 3rd flow path, 24 ... 1st control valve, 25 ... 2nd control valve, 28 ... Temperature control apparatus.

Claims (5)

  A pipe-shaped medium circulation part disposed in a resin injection port side portion in a resin flow path provided in an injection nozzle of an injection molding machine, a cooling medium is supplied into the medium circulation part, and the cooling medium A resin cooling mechanism in an injection molding machine, comprising medium supply control means for controlling supply.   2. The resin cooling mechanism in an injection molding machine according to claim 1, wherein the medium flow part is disposed through the resin injection port side portion of the injection nozzle in a direction intersecting the resin flow direction. .   3. The resin cooling mechanism in an injection molding machine according to claim 1, wherein the medium circulation portion is disposed so as to pass through a central portion of the resin flow path.   The medium supply control means starts supplying the cooling medium using at least one of a resin material, a heating temperature of the injection nozzle, a diameter of the resin injection port, a diameter of the sprue, and a size of the resin molded product as a displacement parameter. The resin cooling mechanism in the injection molding machine according to any one of claims 1 to 3, wherein timing and supply stop timing are controlled.   5. The medium supply control unit according to claim 1, wherein the medium supply control unit supplies a heating medium in addition to the cooling medium in the medium circulation unit and controls supply of the medium. Resin cooling mechanism for injection molding machines.

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