JP6569360B2 - INJECTION DEVICE AND RESIN REPLACEMENT METHOD FOR INJECTION DEVICE - Google Patents

Description

  The present invention relates to an injection apparatus used for a resin injection molding machine and a resin replacement method for the injection apparatus.

  As shown in FIG. 4, the injection device 25 of a general injection molding machine has a heating member 8 such as an electric heater / band heater disposed on the outer peripheral surface thereof, and an injection nozzle at the front end (lower side in FIG. 4). 7 is rotated around the longitudinal axis in the heating cylinder 2 provided with a material supply portion (27-30) such as a material supply hopper above the material inlet 6 at the rear end (upper side in FIG. 4). The screw 26 is arranged to be movable in the axial direction. A spiral flight 26 a is continuously formed on the outer peripheral surface of the screw 26. A continuous resin flow path 26 b partitioned by the flight 26 a is formed between the inner peripheral surface of the heating cylinder 2 and the outer peripheral surface of the screw 26. By rotating the screw 26, a resin material such as a resin pellet supplied from the material supply unit into the heating cylinder 2 is caused to flow toward the injection nozzle 7 via the resin flow path 26b by the flight 26a.

  The shape and size of the screw 26 and the flight 26a are such that the solid (pellet) resin material supplied (input) from the material input port 6 side does not stay in the material input port 6 via the resin flow path 26b. The resin material necessary for one injection filling process is completely plasticized in the reservoir 9 in front of the screw 26 (behind the injection nozzle 7). In order to measure in a stored state (measuring step), each specification is designed from the material inlet 6 side to the injection nozzle 7 side. In addition, each area | region of the said screw which performs said supply, compression, and a measurement may be called a supply part (FZ: Feed Zone), a compression part (CZ: Compression Zone), and a measurement part (MZ: Metering Zone), respectively. Further, for the following explanation, the injection nozzle 7 side of the heating cylinder 2 is referred to as “front” of the injection device, and the material supply part (material input port 6) side is referred to as “rear”, and the screw 26, the resin material, etc. Movement in the direction is defined as “forward” and “backward”. That is, the FZ, CZ, and MZ are designed to be arranged along the front side from the rear side of the screw.

  A screw head 4 continuing to a small diameter portion (not shown) is formed in front of the screw 26, and a check ring 5 (also referred to as a check ring) is attached to the small diameter portion behind the screw head 4. A predetermined amount (the length of the small-diameter portion in the axial direction of the screw 26) is arranged so as to be movable coaxially with the screw 26 in the longitudinal axis direction. The resin material supplied from the material supply unit into the heating cylinder 2 is compressed while flowing forward by the flight 26 a as the screw 26 rotates, and the heat of the heating member 8 disposed on the outer peripheral surface of the heating cylinder 2. In addition to energy, the molten state is formed by thermal energy of shear heat generated by the rotational force of the flight 26a (plasticization step). The resin material (molten resin) in a molten state moves the check ring 5 forward by the resin pressure due to the flow, opens the resin flow path 26b to the screw head 4 side, and It reaches the space (reservoir 9) between the injection nozzle 7 and the screw head 4 via a groove (not shown). During this time, since the injection nozzle 7 is closed by a resin shut-off opening switching valve or the like disposed at the resin inlet of the injection nozzle 7 or a fixed mold (not shown) to which the injection nozzle 7 is docked, The resin pressure of the molten resin that has reached the storage portion 9 also acts on the screw head 4 to retract the entire screw 26. In conjunction with this retraction, the storage portion 9 is expanded and the rotation of the screw 26 and the entire retraction of the screw 26 are continued until a predetermined amount of molten resin is stored, so that the check ring 5 is opened (forward limit position). ) Is maintained (metering step). Note that the plasticizing step and the metering step are distinguished for explanation, and are not clearly distinguished in practice. That is, the plasticizing process is a process from a change in the state of the resin material in the heating cylinder 2 in which the resin material is changed from a solid state to a molten state while flowing in the resin flow path 26b of the injection device 25. The metering step is a description of the specific process performed in the heating cylinder, in which a required amount of molten resin is stored in the storage unit.

  After a predetermined amount of molten resin is stored in the storage portion 9 between the injection nozzle 7 and the screw head 4, when the rotation of the screw 26 is stopped and the screw 26 is advanced at a predetermined speed and a predetermined force, It flows backward to the rear resin flow path 26b. Then, the check ring 5 is moved rearward (retreat limit) by the resin pressure, and the gap between the resin flow path 26 b and the screw head 4 formed between the inner peripheral surface of the heating cylinder 2 and the outer peripheral surface of the screw 26 is increased. Sealing is performed to prevent further backflow of the molten resin to the rear resin flow path 26b. Since the rear resin flow path 26b is sealed, the molten resin is injected and filled into the mold cavity formed by the fixed mold and the movable mold in which the injection nozzle 7 is docked via the injection nozzle 7. (Injection filling process). The rotation and forward / backward movement of the screw 26 described above are performed by driving the plasticizing motor 10a and the gear 11b connected through the gear 10b and the injection motor 11a connected through the ball screw mechanism 11c.

  The injection device that plasticizes the resin material supplied from the material supply unit as described above while flowing forward in the resin flow path by the rotation of the screw is called an inline screw injection device. The in-line screw type injection device is almost completely plasticized on the injection nozzle 7 side (front side) in the heating cylinder 2 when the resin change to change the type of resin material or the color change to change the color. It is necessary to discharge (purge) all of the residual resin material existing in a wide range from the molten state to the unmelted state where plasticization on the material supply unit side (rear side) has not progressed. Hereinafter, the operation of changing the type and color of the resin material is referred to as resin replacement.

  Such discharge of the residual resin material is performed in the vicinity of the injection filling completion position without retreating the screw 26 until all of the resin material supplied to the material inlet 6 is discharged from the heating cylinder 2. (The injection nozzle 7 / injection device 25 is in a state of being separated from the mold, and the residual resin material discharged from the injection nozzle 7 is received by a large container or the like). After confirming the discharge of all the remaining resin material, the inside of the heating cylinder 2 is cleaned if necessary, and after confirming that no resin material remains in the heating cylinder 2, a new color or type The resin material is supplied from the material supply unit. Alternatively, the resin of the molded product is completely new by starting the supply of a new color or type of resin material from the material supply unit while the resin material remains in the heating cylinder 2 without discharging the residual resin material. The molding cycle is continuously performed until the color or type is switched (the molded product formed during that time is discarded as a defective product).

  In any of the above resin changing methods, it takes time to discharge all the remaining resin materials and clean the inside of the heating cylinder thereafter, or many defective products mixed in color and type are discarded. The occurrence of time loss and defective products for resin replacement has been pointed out as a problem that reduces the production efficiency of molded products.

  In recent years, there has been an increasing tendency to produce a variety of products in small quantities, producing many products of different colors from a single mold. In order to cope with this, for example, as shown in FIG. 4, pneumatic feeding or the like is possible between a plurality of resin storage tanks 27 in which different resin or colored resin materials are stored and the hopper 30 of the injection device 25. A resin material supply method is also adopted in which the resin storage tank 27 to be used is switched by the switching valve 29 or the like in the transport pipe 28 and communicated by the transport pipe 28.

  However, in this case, in addition to the residual resin material in the heating cylinder 2 described above, the solid remaining in the transport pipeline of the material supply section from the resin storage tank 27 to the hopper 30 via the switching valve 29. It is necessary to discharge the resin-like resin material out of the transportation pipeline including the transportation piping 28 every time the resin is changed.

  Regarding resin replacement in the in-line screw injection apparatus as described above, a molding material supply apparatus described in Patent Document 1 has been proposed.

  In the molding material supply apparatus described in Patent Document 1, a plurality of hopper portions having individual supply paths are arranged on the same circumference on the turntable via shutter members, respectively. By rotating, the individual supply path of the hopper connected to the common supply path for supplying the molding material to the injection device is selectively switched.

  Further, in Patent Document 2, in order to solve the laterally long problem of the injection device, the primary screw that supplies the material and the secondary screw that performs the injection are divided, and the primary screw is placed on the rear upper side of the secondary screw. Vertically arranged injection devices have been proposed.

JP 2001-293750 A JP-A-7-251433

  Since the molding material supply apparatus described in Patent Document 1 supports multi-product small-quantity production, a plurality of hoppers that supply resin materials to the injection apparatus are arranged on a turntable on the material input port of the injection apparatus, and are rotated. The hopper is rotated to directly switch the hopper that supplies the resin material to the material inlet of the injection device. Therefore, as shown in FIG. 4, in the form of multi-product small-quantity production where a plurality of resin storage tanks are connected to the hopper of the injection device by a transportation pipe, the solid resin material remaining in the transportation pipe is removed. It is not necessary to discharge outside the transportation pipeline including the transportation piping 28. However, it does not contribute at all to the solution of the problem of discharging the residual resin material from the heating cylinder in the resin replacement of the in-line screw type injection device.

  Moreover, in the injection apparatus of patent document 2, the resin material is supplied from the hopper arrange | positioned at the upper part of the primary screw arrange | positioned vertically. However, there is no description of switching a plurality of hoppers in order to cope with a variety of small-quantity production, etc., and the solution of the problem of discharge of residual resin material from the heating cylinder as in Patent Document 1. Does not contribute to anything.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an injection apparatus and a resin replacement method for an injection apparatus that can easily and quickly perform resin change / color change compatible with low-mix production.

In order to solve the above problems, an injection apparatus or a resin replacement method for an injection apparatus according to the present invention includes the following features.
(1) A heating cylinder, a rotary table frame disposed above the heating cylinder, a rotary table supported rotatably above the rotary table frame, and a plurality of hoppers disposed above the rotary table The heating cylinder incorporates the first screw and has a material insertion port for introducing the resin material into the heating cylinder. The hopper incorporates the second screw and heats the resin material in the hopper. A heating member that includes a material supply port that supplies a resin material to a material input port of the heating cylinder and an open / close switching unit that switches opening and closing of the material supply port. Each of the material supply ports has a through hole that allows the material supply port of the hopper and the material input port of the heating cylinder to communicate with each other. An injection apparatus, wherein a material supply port of a hopper communicated can be arbitrarily selected from a plurality of hoppers.

  According to the feature (1) above, a configuration (configuration 1) in which a part of the screw (second screw) is arranged in the hopper is provided for each resin material. And according to the resin material to be used, this structure 1 is further provided with the structure (structure 2) arbitrarily selected with a turntable and connected to a heating cylinder. With these configurations 1 and 2, when the resin is changed, only the resin material in the heating barrel (first screw) can be discharged as the “residual resin material”. It is not necessary to discharge as. Therefore, it is possible to provide an injection apparatus that shortens the time required for discharging the “residual resin material”.

  (2) In the injection device according to (1), the second screw rotates in the hopper when the opening / closing switching unit is closed, thereby agitating the resin material in the hopper, and the resin material in the hopper, It has at least one kneading function for kneading the functional additive.

Each hopper also includes a heating member. According to the feature (2) above, when the resin is changed, the residual resin material in the heating cylinder is discharged (purged) or while the molding process is being performed using one hopper. With the open / close switching part of the other hopper closed, by operating the heating member or the second screw, the resin material in the hopper is agitated, and the heating member causes the resin material to be uniformly preheated or dried. Thus, the resin material in the hopper can be maintained in a state suitable for supply to the material inlet of the heating cylinder. As a result, it is possible to shorten the start-up time of the molding process using a new resin material after resin replacement and the transition time to stable molding, and the resin replacement can be performed quickly.

Further, when injection molding is performed by adding a functional additive such as reinforcing fiber to the resin material, the heating member or the second screw is operated in a state in which the opening / closing switching portion of the hopper is closed. The resin material and the functional additive are kneaded, and the heating material is used to uniformly preheat and dry the resin material and the functional additive. Even with such a special mixed resin material, uniform preheating and drying are performed. Can be performed in advance. In this way, in the standby hopper with the open / close switching unit closed, the resin material or mixed resin material is maintained in a state suitable for supply to the material input port of the heating cylinder, so that the injection molding after the resin change The start-up time and the transition time to stable molding can be shortened, and the resin can be replaced quickly. In addition, even if it is the 2nd screw which has an agitation function and a kneading function in the state where the opening / closing switching part of the hopper is closed, the original supply function is exhibited with the opening / closing switching part opened. It goes without saying that it is done.

  (3) In the injection apparatus according to any one of (1) and (2), the injection apparatus is configured such that the rotary table can be moved up and down with respect to the heating cylinder.

  According to the feature (3) above, any one location in the pipe line between the material supply port of the hopper on the rotary table and the material input port of the heating cylinder is configured to be able to contact and separate in the vertical direction. Can do. Therefore, by adopting a configuration in which the rotary table is raised and rotated while being separated from the heating cylinder, and the rotary table is lowered and the selected hopper is connected to the heating cylinder, the connection and separation of the pipe line is achieved. For the configuration of the portion, only the connection / separation in the vertical direction, such as an inlay, may be considered. The same applies to the seal member that is disposed at the contact / separation portion of the pipe line to ensure airtightness at the time of connection, and easily ensures the airtightness at the time of connection of the contact / separation part of the pipe line. Can do. Further, even when a resin material is clogged in the pipe line between the material input port of the heating cylinder from the hopper, the pipe line can be easily accessed by raising the rotary table.

  (4) It has a heating cylinder, a rotary table frame disposed above the heating cylinder, a rotary table supported rotatably above the rotary table frame, and a plurality of hoppers disposed above the rotary table. The heating cylinder incorporates the first screw and has a material insertion port for introducing the resin material into the heating cylinder. The hopper incorporates the second screw and heats the resin material in the hopper. A rotary table for an injection apparatus comprising a heating member that has a material supply port for supplying a resin material to a material input port of a heating cylinder and an open / close switching unit that switches opening and closing of the material supply port. And the material supply port of the hopper communicated with the material input port of the heating cylinder is arbitrarily selected from a plurality of the hoppers. For example method.

  (5) In the resin changing method according to (4), in at least one hopper other than the hopper having a material supply port connected to the material input port of the heating cylinder, the heating member of the hopper and the hopper are incorporated in the hopper At least one of the second screws is operated, and at least the resin material in the vicinity of the material supply port in the hopper is maintained in a state suitable for supply to the material receiving port of the heating cylinder.

According to the above feature (4) or (5), each hopper includes a heating member and a second screw. Therefore, when the resin is changed, while the residual resin material in the heating cylinder is being discharged (purged), or while the molding process is being performed using one hopper, By operating the second screw, the resin material in the hopper is agitated, the resin material is uniformly preheated and dried, and the resin material in the hopper is suitable for supply to the material receiving port of the heating cylinder. Can be maintained in a state. As a result, it is possible to shorten the start-up time of the molding process using a new resin material after resin replacement and the transition time to stable molding, and it is possible to perform resin replacement quickly.

  According to the present invention, it is possible to provide an injection apparatus and a resin replacement method for an injection apparatus that can easily and quickly perform resin change / color change that can be applied to a variety of small-quantity production.

It is a figure which shows an example of the injection device which concerns on this invention. It is a top view which shows an example of arrangement | positioning of the hopper on the rotary table used for the injection device which concerns on this invention. It is a figure which shows the other Example of the injection device which concerns on this invention. It is a figure which shows an example of the form corresponding to high-mix low-volume production with a common injection device.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a view showing an injection apparatus 1 according to an embodiment of the present invention. The injection device 1 in this embodiment includes a heating cylinder 2, a rotary table base 12c disposed above the heating cylinder 2, a rotary table 12 rotatably supported above the rotary table base 12c, and the rotary table 12 above. The heating cylinder 2 includes a first screw 3 and a material charging port 6 for charging a resin material into the heating cylinder 2, and includes a plurality of hoppers 15 disposed in the heating cylinder 2. Each of the hoppers 15 includes a second screw 16 and a heating member 19 that heats the resin material in the hopper, and supplies the resin material to the material inlet 6 of the heating cylinder 2 on the rotary table 12 side. The rotary table 12 includes a material supply port 17 and an opening / closing switching unit 18 for switching opening and closing of the material supply port 17, and the rotary table 12 is provided for each material supply port 17 of the hopper 15. The material supply port 17 of the hopper 15 which has the through-hole 13 which connects the supply port 17 and the material input port 6 of the heating cylinder 2 and rotates the rotary table 12 and is connected to the material input port 6 of the heating cylinder 2. Can be arbitrarily selected from a plurality of hoppers 15, that is, a hopper for supplying a resin material to the heating cylinder 2 can be arbitrarily selected from a plurality of hoppers arranged on the upper surface of the turntable. The injection device of this embodiment also has the same mechanism as a known injection device in which a resin material is supplied from the hopper 15 into the heating cylinder 2 and the resin material is injected from the injection nozzle 7 at the tip of the heating cylinder 2. Therefore, the following description will focus on the features specific to this embodiment.

  The heating cylinder 2 in the present embodiment plasticizes (melts) the resin material supplied to the material charging port 6 in the resin flow path, and then measures a predetermined amount in the storage unit 9, and then sends a gold (not shown) from the injection nozzle 7. The point of injection into the mold cavity is the same as the heating cylinder in the conventional injection apparatus shown in FIG. However, the heating cylinder 2 in the present embodiment is different from the conventional heating cylinder in the configuration of the first screw 3.

  The 1st screw 3 of a present Example is short compared with the conventional screw. This is because the second screw 16 incorporated in the heating hopper 15 described later has a function of a resin material supply part FZ, and the first screw 3 has a function of a compression part CZ and a weighing part MZ. It is enough to secure it.

  Next, the material supply part which supplies the resin material in the heating cylinder 2 in a present Example is demonstrated. The material supply unit in the present embodiment includes a plurality of hoppers 15 and a rotary table 12 that supports the lower sides of the plurality of hoppers 15 on the upper surface side. Each of the hoppers 15 includes a hopper material receiving port 20 through which material is supplied to each hopper and a heating member 19 such as a band heater. The second screw 16 is built in, and a material supply port 17 and a material supply are provided below. An opening / closing switching unit 18 for switching opening and closing of the mouth 17. The rotary table 12 is formed with through holes 13 for communicating each of the material supply ports 17 of the hopper 15 with the material input port 6 of the heating cylinder 2, and a rotary table drive motor via the gear 12b. It is rotationally driven by 12a.

  By the way, as the rotary table 12 rotates with respect to the heating cylinder 2, the pipe line between the material supply port 17 of the hopper 15 on the rotary table 12 and the material input port 6 of the heating cylinder 2 is connected to the pipe line. A dividing surface (discontinuous portion) perpendicular to the longitudinal direction is required. Further, while the resin material is being supplied from the hopper 15 to the heating cylinder 2, the resin material is not discharged to the outside of the pipeline between the divided surfaces, and the entry of contaminants and the like from the outside can be prevented. It must be airtight. On the other hand, while the turntable 12 is rotated, the divided surfaces must have slidability while avoiding metal contact between the surfaces. To that end, at least one surface of the divided surfaces is required. It is necessary to arrange a sealing member having flexibility, heat resistance, wear resistance, and the like.

  The rotary table 12 is rotatably supported on the rotary table base 12c via the rotary shaft 14, and the rotary table base 12c is supported from the heating cylinder 2 and disposed above the rotary table base 12c. In addition, a connecting member 12d penetrating the rotary table base 12c is connected above the material input port 6 of the heating cylinder 2 via a seal member 6a. A sealing member 13a is disposed above the coupling member 12d, and the contact state between the coupling member 12d and the lower surface of the rotary table 12 is maintained via the sealing member 13a. The through hole 13 of the table 12 and the connecting member 12d are communicated.

  These sealing members 6a and 13a maintain the predetermined airtightness of the connected pipe line when the through hole 13 of the turntable 12 and the material input port 6 of the heating cylinder 2 are communicated by the coupling member 12d, and When rotating the turntable 12, it is arranged to avoid metal contact between the lower surface of the turntable 12 and the upper surface of the connecting member 12d. Further, due to differences in processing / assembly tolerances and thermal expansion of members constituting the pipe line, and also due to rotation tolerances of the rotary table 12, the connecting member 12d is subjected to various magnitudes of stress from various directions. Works. These seal members 6a and 13a also have the purpose of protecting the members constituting the pipe line from such stress, and only above the connecting member 12d (the seal member 13a) that is kept in contact with the lower surface of the rotary table 12. In addition, it is preferable to be disposed below (seal member 6a), and for such purposes, a material such as silicon resin having elasticity, heat resistance, wear resistance, etc. may be employed. preferable.

  FIG. 2 is a plan view of the rotary table 12 of this embodiment as viewed from above. In the present embodiment, four hoppers 15 are arranged on the upper surface of the turntable 12 as shown in FIG. The four hoppers 15 are installed symmetrically with respect to the rotation center of the turntable 12. Thus, by rotating the rotary table 12, each material supply port 17 of the hopper 15 can be communicated with the material input port 6 of the heating cylinder 2. Further, by arranging them symmetrically with respect to the rotation center, it is possible to stably rotate and support the turntable 12 without biasing the load applied to the turntable 12c that supports the turntable 12. The number of hoppers 15 may be even or odd as long as they are arranged symmetrically with respect to the center of rotation, and need not be limited to four.

  In the present embodiment, the lower side of the plurality of hoppers 15 is supported on the upper surface side of the rotary table 12, but the support mode on the upper surface side of the rotary table of the present invention is limited to this. It is not a thing. For example, although not illustrated, the lower end portion of the material supply port 17 of each hopper 15 may have a form in which the rotary table 12 is penetrated and protruded to the lower surface side of the rotary table 12.

  Below, each structure of a material supply part is explained in full detail. A heating member 19 such as a band heater is disposed around each outer peripheral surface of the plurality of hoppers 15 supported by the rotary table 12. The heat energy of these heating members is transmitted to the resin material in the hopper 15.

  As a feature of the present embodiment, the hopper 15 incorporates a second screw 16. Similar to the first screw 3, the second screw 16 has a second flight 16a. And the 2nd screw 16 is rotationally driven by the 2nd screw drive motor 21a via the gears 21b and 21c.

  Further, the hopper 15 further includes a material supply port 17 for supplying a resin material to the material input port 6 of the heating cylinder 2 below, and an opening / closing switching unit 18 for switching opening and closing of the material supply port 17. . The second screw 16 has a function of the resin material supply unit FZ, and is supplied from the hopper material receiving port 20 into the hopper 15 when the second screw 16 is rotated with the opening / closing switching unit 18 opened. The made resin material can be flowed from the upper side to the lower material supply port side.

Further, in the present embodiment, when the second screw 16 is rotated in a state where the opening / closing switching portion 18 is closed, the resin material that has flowed downward from above in the hopper 15 causes the resin material that has flowed downward from the top to the inside of the hopper 15 and the second screw. The resin material can be caused to flow upward again from a gap (not shown) between the outer diameters of the 16 second flights 16 a to stir the resin material in the hopper 15 in the vertical direction. That is, the second screw 16 also has a function of stirring the resin material in the hopper 15. Such appropriate rotation control (rotation speed and rotation torque) of the second screw 16 having a function of stirring the resin material in the hopper 15, and appropriate heating control of the resin material in the hopper 15 by the heating member 19, By the above, uniform preheating and drying of the resin material in the hopper 15 can be performed.

Therefore, at the time of changing the resin, while the residual resin material in the heating cylinder 2 is being discharged (purged), or while injection molding is being performed using one hopper 15, the other hoppers 15 that are standing by are waiting. By operating the heating member 19 and the second screw 16, the resin material in the waiting hopper 15 is uniformly preheated and dried, and the resin material in the hopper 15 is used as the material of the heating cylinder 2. It can be maintained in a state suitable for supply to the receiving port 6.

On the other hand, when injection molding is performed by adding a functional additive such as a reinforcing fiber to the resin material, the kneading function of the functional additive and the resin material is performed with the open / close switching portion 18 of the hopper 15 closed. By adopting the combination of the second screw 16 and the hopper 15 having some of the hoppers, uniform preheating and drying of such a special mixed resin material can be performed in advance. In this way, the mixed resin material is maintained in a state suitable for supply to the material inlet 6 of the heating cylinder 2 in the standby hopper 15 in which the open / close switching portion is closed. The start-up time and the transition time to stable molding can be shortened, and the resin can be replaced quickly. Even if the second screw 16 has a stirring function and a kneading function with the opening / closing switching portion 18 of the hopper 15 closed, the original supply function is exhibited with the opening / closing switching portion 18 opened. It goes without saying that it is configured to do so.

  The turntable 12 is rotationally driven by a turntable drive motor 12a via a gear 12b. Further, the rotary table 12 is rotatably supported on the rotary table base 12c via the rotary shaft 14. As described above, the rotary table base 12 c is supported from the heating cylinder 2.

  Generally, the heating cylinder 2 is disposed on a base portion (not shown) so as to be movable in the longitudinal direction in order to adjust the docking position to the die for each die. Therefore, the rotary table base 12c is specifically supported by a main body portion of the heating cylinder 2 or a support member (not shown) of the heating cylinder 2 that moves integrally with the heating cylinder 2 and moves relative to a base portion (not shown). Arranged above the cylinder 2. In a general injection molding machine, a work floor is often provided above the heating cylinder 2 for maintenance of a material supply hopper, a heating member on the outer peripheral surface of the heating cylinder, and the like. The structure 12c may also serve as the work floor.

  On the other hand, the rotary table base 12 c is not necessarily supported by the heating cylinder 2 or a member that can move integrally with the heating cylinder 2. The rotary table base 12c may be supported from a member independent of the heating cylinder 2 or from the floor surface. In this case, the rotary table base 12c itself is also configured to be movable in the longitudinal direction of the heating cylinder 2, and it is necessary to adjust the position of the rotary table base 12c according to the adjustment of the docking position of the heating cylinder 2 performed for each mold. There is. However, from the structural viewpoint of the heating cylinder 2, it is not necessary to support the load of the entire material supply unit including the rotary table base 12c, the rotary table 12, and the plurality of hoppers 15 on the heating cylinder 2 side. There may be a case where it is preferable to support the rotary table base 12c from a member independent of the heating cylinder 2 or from the floor surface, which does not require an increase in support rigidity or the like on the heating cylinder 2 side. Further, in the case of this embodiment, from the viewpoint of maintenance of the heating cylinder 2, the heating table 2c is moved from above the heating cylinder 2, or the heating cylinder 2 is pulled out from the lower side of the rotation table base 12c. 2 is improved, and maintenance of the heating cylinder 2 is improved. In view of these, the support form of the rotary table base 12c may be selected as appropriate.

The method for supplying the resin material into the heating cylinder 2 by the hopper 15 and the rotary table 12 described above is as follows. Note that the second screw 16 has a stirring function.
First, the material supply port 17 of a certain hopper 15 is closed by the open / close switching unit 18, and the resin material is supplied from the hopper material receiving port 20 of the hopper 15 into the hopper 15. At this time, since the resin material is in an unmelted solid state (pellet shape), the hopper material receiving port 20 preferably uses a receiving port and a guide tube having a relatively large diameter or diameter. Moreover, if the 2nd screw 16 has a kneading function, you may supply functional additives, such as a reinforced fiber, with a resin material.

While the resin material is being supplied into the hopper 15 or while a predetermined amount is being supplied, the heating member 19 and the second screw drive motor 21a are started to be driven with the open / close switching portion 18 of the hopper 15 closed. To do. Then, the resin material in the hopper 15 is agitated by the second screw 16 and is uniformly preheated and dried by the heating member 19. Depending on which resin material is supplied to which hopper 15 and at what timing the resin material is supplied to the heating cylinder 2, the start timing of stirring, preheating and drying of the resin material in each hopper 15 is determined. . Further, in order to maintain the resin material in a state suitable for supply to the material receiving port 6 of the heating cylinder 2 in the standby hopper 15 in accordance with the timing of supplying the resin material to the heating cylinder 2, the hopper 15 The rotation control of the second screw 16 appropriate for the stirring of the resin material in the inside and the heating control of the heating member 19 appropriate for preheating and drying of the resin material in the hopper 15 are performed (standby mode).

Next, when the timing for supplying the resin material in a certain hopper 15 to the heating cylinder 2 is reached, the rotary table drive motor 12a is driven, and the material supply port of the hopper 15 containing the preheated and dried resin material uniformly. The rotary table 12 is rotated so that 17 communicates with the material inlet 6 of the heating cylinder 2 extended to the lower surface of the rotary table 12 by the connecting member 12d through the through hole 13. The rotational position adjustment of the rotary table 12 may be direct rotational position adjustment using a proximity switch or the like arranged on the rotary table 12, or rotational position adjustment by detecting the rotational angle of the rotary shaft 14 with an encoder or the like. Alternatively, a servo motor may be employed as the second screw drive motor 21a to improve the rotational positioning accuracy. Further, for the position holding and positioning of the rotary table 12 after adjusting the rotational position, it is preferable to provide a rotation prevention / positioning mechanism by an external force such as a knock pin. As described above, the lower surface of the turntable 12 is configured to maintain a contact state via the seal member 13a so that the lower surface of the turntable 12 does not make metal contact with the upper portion of the connecting member 12d when rotating. It is.

  After adjusting the rotational position of the rotary table 12, the material supply port 17 of the hopper 15 is opened by the opening / closing switching unit 18, and the rotation control of the second screw 16 of the hopper 15 and the heating control by the heating member 19 are performed. Is shifted from the standby mode to the continuous molding mode. The resin material is continuously supplied from the hopper material receiving port 20 to the hopper 15, and the resin material in the hopper is rotated to the material input port 6 of the heating cylinder 2 through the connecting member 12 d by the rotational drive of the second screw 16. Feed continuously. After being supplied to the heating cylinder 2, the resin material plasticized and measured by the first screw 3 is injected from the injection nozzle 7 in the heating cylinder 2.

Thus, according to the hopper 15 of the present embodiment including the heating member 19 and the second screw 16, the resin material in the hopper 15 is agitated in a standby state in which the resin material is not supplied from the hopper 15 to the heating cylinder 2. Thus, the resin material is uniformly preheated and dried, and the resin material in the hopper 15 can be maintained in a state suitable for supply to the material inlet 6 of the heating cylinder 2 (standby mode). In this way, by maintaining the resin material in a state suitable for supply to the material inlet of the heating cylinder in the standby hopper 15, the injection molding start-up time after resin replacement and the transition to stable molding are performed. The time can be shortened and the resin can be changed quickly.

  On the other hand, when the resin material is supplied from the hopper 15 to the heating cylinder 2, the resin material introduced into the hopper 15 from the hopper material receiving port 20 is supplied to the heating cylinder 2 while being heated (continuous molding mode). In the present embodiment, as described above, the function of the supply unit FZ that has been conventionally given to the screw in the heating cylinder is given to the second screw 16 in the hopper 15. It is.

  Thereby, the 1st screw 3 in the heating cylinder 2 should just be provided with the function as a compression part CZ and the measurement part MZ, and can shorten the length. As the first screw 3 is shortened, the internal capacity of the heating cylinder 2 is also reduced, so that the volume of residual resin material to be discharged (purged) at the time of resin change is also reduced, and the working time at the time of resin change is shortened. it can.

  The material supply port 17 of the hopper 15, the through-hole 13 of the rotary table 12, the inner pipe line of the connecting member 12 d, and the inner diameter of the material input port 6 of the heating cylinder 2 communicate with each other so that the resin material smoothly flows into the heating cylinder 2. For example, each can have substantially the same inner diameter. Further, since the resin material flows from above in the order of the material supply port 17, the through-hole 13, the connecting member 12 d inner pipe line, and the material receiving port 6, the inner diameter of the member positioned lower is the inner diameter of the member positioned higher If it is narrower, the resin material will remain at the level difference caused by the difference in inner diameter, which may cause clogging or resin mixing after resin replacement. Therefore, the inner diameter of the lower part is the upper part. It is preferable to make the inner diameter of the same or slightly wider.

  The shape and size of the first screw 3 and the first flight 3a in the heating cylinder 2 are suitable for measurement in the resin flow path until the resin material supplied to the material charging port reaches the check ring 5. As described above, it is designed to be stored in the storage portion 9 in front of the heating cylinder 2 in the plasticized state (molten state).

  In the present embodiment, if the second screw 16 in the hopper 15 is conventional, the function as the supply unit FZ provided to the screw in the heating cylinder and the stirring function of stirring the resin material in the hopper 15 are used. It has been explained that On the other hand, it has also been explained that the second screw 16 in the hopper may have a kneading function between a functional additive such as a reinforcing fiber and a resin material.

When injection molding is performed by adding a functional additive such as a reinforcing fiber to the resin material, the second screw 16 having the above-described mixed function is incorporated among the plurality of hoppers 15 supported by the rotary table 12. If there is a hopper 15 to be used, a functional additive is supplied to the hopper 15 together with the resin material, and the second screw 16 in the hopper 15 is operated so that the mixed resin material is sufficiently time-consuming in advance. And kneaded. Furthermore, by using the heating member 19 in combination, the mixed resin material can be uniformly preheated and dried. In this way, by maintaining the resin material in a state suitable for supply to the material inlet 6 of the heating cylinder 2 in the standby hopper 15, the injection molding start-up time after resin replacement and stable molding can be achieved. The transition time can be shortened, and even when a mixed resin material is used in which a functional additive is added to the resin material, the resin can be replaced quickly. In addition, when the 2nd screw 16 of the hopper 15 is given a mixing function, the supply function of the 2nd screw 16 may fall. In such a case, the material supply port 6 side of the first screw 3 of the heating cylinder 2 is supplementarily provided with a supply function, and the resin material from the material supply port 17 of the hopper 15 to the material input port 6 of the heating cylinder 2 is supplied. It is preferable to assist the flow.

Next, another embodiment of the present invention will be described.
In the embodiment described above, the rotary table 12 that supports the hopper 15 is rotatably supported on the rotary table base 12c supported from the heating cylinder 2 above the heating cylinder 2. In the present embodiment, the rotary table 12 is not only rotatably supported by the rotary table base 12c, but also the rotary table 12 is configured to be movable up and down with respect to the rotary table base 12c.

  FIG. 3 is a view showing an injection apparatus 22 according to another embodiment of the present invention. The injection device 22 is provided with an elevating mechanism 52 in order to achieve both the rotation support of the rotary table 12 and the configuration that enables the rotary table 12 to be raised and lowered with respect to the rotary table base 12c. Is different. The elevating mechanism 52 rotates and supports the rotary shaft 14 of the rotary table 12 and also supports a rotary drive system including a rotary table drive motor 12a for rotating the rotary table 12 and a gear 12b for rotation transmission. 52a and an elevating actuator 52b for elevating the elevating base 52a relative to the rotary table base 12c. The elevating mechanism 52 is an example and is not limited to the described form.

  Since the rotation driving of the rotary table 12 has already been described, the lifting and lowering operation of the rotary table 12 with respect to the rotary table base 12c, which is a feature of this embodiment, will be described. FIG. 3 shows a state where the lifting mechanism 52 is operated and the rotary table 12 is in the ascending limit position with respect to the rotary table base 12c. Specifically, in the stationary state where the rotary table 12 is not rotationally driven, the lift base 52a is moved to its lift limit position by the lift actuator 52b composed of a hydraulic cylinder or the like fixed to the turntable base 12c. Raise. By the raising operation of the elevating base 52a, the rotary table 12 is raised to the ascending limit position vertically with respect to the rotary table base 12c. The rotation prevention / positioning mechanism of the rotary table 12 described above may be configured to be released before the raising / lowering actuator 52b is operated or to be released by the raising operation of the rotary table 12.

  FIG. 3 shows a form in which the lift base 52a is directly lifted by the lift actuator 52b. Here, the communication between the material supply port 17 of the hopper 15 (the through hole 13 of the rotary table 12) and the material input port 6 (the connecting member 12d) of the heating cylinder 2 needs to be positioned with a predetermined rotational position accuracy. There is. Therefore, although not shown, it is preferable that a guide member for guiding the raising / lowering of the lifting base 52a is arranged on the rotary table base 12c and then the lifting base 52 is lifted / lowered by the lifting / lowering actuator 52b.

  Further, the configuration of the contact / separation portion between the through hole 13 of the turntable 12 and the connecting member 12d only needs to consider the connection / separation in the vertical direction such as an inlay. Specifically, as shown in FIG. 3, a convex guide portion 13 b continuous with the through hole 13 of the turntable 12 is formed on the lower surface of the turntable 12 for each through hole 13, and the upper surface of the connecting member 12 d is A concave guide portion 12e corresponding to the convex guide portion 13b may be formed. In the concavo-convex structure such as the convex guide portion 13b and the concave guide portion 12e, it is easy to dispose a seal member for ensuring predetermined airtightness of the contact / separation portion.

  For example, as shown in FIG. 3, the seal member 13a may be disposed on the upper surface of the connecting member 12d. Although not shown, the bottom surface or side surface of the concave guide portion 12e of the connecting member 12d, or the through hole 13 is used. You may arrange | position to the bottom face or side surface of the convex guide part 13b. Further, if the seal member 13a is arranged not only at one place but also at a plurality of places described above, high airtightness at the time of connection at the contact / separation portion can be easily ensured.

  On the other hand, by adopting a concavo-convex structure that guides the convex guide portion 13b and the concave guide portion 12e with the taper surfaces in the vertical direction, the lifting / lowering operation of the rotary table 12 can be used while having a simple structure. It can also be a rotational positioning mechanism. The concave / convex structure such as the convex guide portion 13b and the concave guide portion 12e is not limited to the concave / convex structure guided by the mutually perpendicular taper surfaces. Alternatively, it may be a concave shape, and an appropriate shape may be selected in view of the arrangement of the seal member 13a.

  In the form in which the rotary table 12 is raised and lowered with respect to the rotary table base 12c, not only the merit related to the configuration of the contact / separation portion between the through hole 13 of the rotary table 12 and the connecting member 12d, but also the hopper 15 Even when a clogging of resin material or the like occurs in the material supply port 17 (through hole 13 of the rotary table 12), the connecting member 12d, or the like between the hopper 15 and the material receiving port 6 of the heating cylinder 2, the rotary table is also used. By raising 12, access to these conduits is easy.

  Although not shown, the rotary table 12c may be lifted and lowered with respect to the heating cylinder 2 instead of the rotary table 12 with respect to the rotary table 12c. In this case, the elevating base 52a is not necessary, but the contact / separation portion in the pipe line from the material supply port 17 of the hopper 15 to the material input port 6 of the heating cylinder 2 is below the connecting member 12d and the material of the heating cylinder 2. It is between the receiving port 6. Further, it is structurally somewhat complicated to support the rotary table base 12c from the heating cylinder 2 via the lifting actuator 52b.

  Therefore, in reality, as described above, the rotary table base 12c is supported from a member independent of the heating cylinder 2 or from the floor surface. The rotary table base 12c itself needs to be configured so that the position of the rotary table base 12c can be adjusted in accordance with the adjustment of the docking position of the heating cylinder 2 performed for each mold. If it raises with respect to 2, there also exists an advantage that the accessibility to the outer peripheral surface of the heating cylinder 2 and the material receiving port 6 of the heating cylinder 2 improves. In view of these, the form of the lifting mechanism of the rotary table 12 may be selected as appropriate.

  Although one embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to this embodiment, and various modifications can be made without departing from the spirit of the invention. Not too long. For example, in the latter embodiment, the form in which the rotary table 12 is raised and lowered has been described. However, the pipe line from the material supply port 17 of the hopper 15 to the material reception port 6 of the heating cylinder 2 is separated from the beginning at an arbitrary position. A configuration in which a configuration that can be extended in the vertical direction and can be arbitrarily contacted / separated on the other pipe end face is provided on either or both of the upper and lower pipe end faces. Also good. In this embodiment, when the rotary table 12 is rotated, the pipe line is separated, and when the resin material is supplied from the arbitrary hopper 15 to the heating cylinder 2, the pipe line may be connected. If it is this form, in order to ensure the predetermined airtightness of this contact-and-separation part as demonstrated previously, without raising / lowering the rotary table 12 or the rotary table base 12c in which the several hopper 15 is arrange | positioned upwards It is possible to adopt a configuration in which the arrangement of the seal member is easy.

DESCRIPTION OF SYMBOLS 1,22 Injection apparatus 2 Heating cylinder 3 1st screw 3a 1st flight 4 Screw head 5 Check ring 6 Material input port 6a Sealing member 7 Injection nozzle 8, 19 Heating member 9 Storage part 10a Plasticizing motor 10b Gear 11a Injection motor 11b Gear 11c Ball screw mechanism 12 Rotary table 12a Rotary table drive motor 12b Gear 12c Rotary table base 12d Connecting member 12e Concave guide part 13 Through hole 13a Seal member 13b Convex guide part 14 Rotary base rotary shaft 15 Hopper 16 Second screw 16a First 2 Flight 17 Material supply port 18 Open / close switching unit 20 Hopper material receiving port 21a Second screw drive motors 21b, 21c Gear 52 Lifting mechanism 52a Lifting base unit 52b Lifting actuator

Claims (3)

A heating cylinder;
A turntable base disposed above the heating cylinder;
A rotary table rotatably supported above the rotary table base;
A plurality of hoppers disposed above the rotary table;
Have
The heating cylinder incorporates a first screw and has a material inlet for charging a resin material into the heating cylinder.
The hopper includes a second screw, a heating member that heats the resin material in the hopper, and a material supply port that supplies the resin material to the material input port of the heating cylinder on the rotary table side. An open / close switching unit that switches open / close of the material supply port,
The rotary table has a through-hole for communicating the material supply port of the hopper and the material input port of the heating cylinder for each material supply port of the hopper, and rotates the rotary table, the material supply port of the hopper which communicates with the material inlet of the heating cylinder, Ri arbitrarily selected der from the plurality of hoppers,
The second screw has a stirring process for stirring the resin material in the hopper, and the resin material and the functional additive in the hopper are kneaded in the hopper whose material supply port is closed by the opening / closing switching unit. The rotation is controlled to execute at least one of the kneading process to be performed,
In the hopper in which the material supply port is closed by the opening / closing switching unit, the rotation control for the second screw and the heating control for the heating member are performed, thereby preheating the resin material in the hopper or An injection apparatus configured to be able to perform drying . The injection device according to claim 1 , wherein
The injection apparatus, wherein the rotary table is configured to be movable up and down with respect to the heating cylinder. A heating cylinder;
A turntable base disposed above the heating cylinder;
A rotary table rotatably supported above the rotary table base;
A plurality of hoppers disposed above the rotary table;
Have
The heating cylinder incorporates a first screw and has a material inlet for charging a resin material into the heating cylinder.
The hopper includes a second screw, a heating member that heats the resin material in the hopper, and a material supply port that supplies the resin material to the material input port of the heating cylinder on the rotary table side. For an injection device having an open / close switching unit that switches open / close of the material supply port,
While rotating the rotary table, arbitrarily selecting the material supply port of the hopper communicated with the material input port of the heating cylinder from a plurality of the hoppers ,
In at least one hopper other than the hopper having the material supply port communicated with the material input port of the heating cylinder, the material supply port is closed by the opening / closing switching unit, and the resin material in the hopper is stirred. The second screw is rotated so that at least one of a stirring process and a kneading process for kneading the resin material and the functional additive in the hopper is performed, and the resin material in the hopper is moved by the heating member. By heating, at least the resin material in the vicinity of the material supply port in the hopper is preheated or dried, and is maintained in a state suitable for supply to the material input port of the heating cylinder . Resin change method.

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