JP2019115994A - Injection molder - Google Patents

Abstract

To provide an injection molder capable of stably securing a desired quality of a completed molded article by controlling a state of an injection material before injection to a cavity.SOLUTION: An injection molder 1 of this invention comprises: a cylindrical heating cylinder 20 including a nozzle 22; a screw 30 in which a hole 31 is formed; a heater 40 provided in a heating area HAr in an axial direction and heating a molten molding material PT that is supplied; a sensor 60 disposed in the screw 30, detecting an indicator indicating a state of the molten molding material PT located in the heating area HAr, and outputting an output signal of the indicator; a control unit 80 disposed in a non-heating area NHAr and executing predetermined processing to the output signal S1 of the first sensor 60; and a connection wire 90 provided in the hole 31 of the screw 30 and electrically connecting the first sensor 60 and the control unit 80.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an injection molding machine.

  Conventionally, as resin molding, one using an injection molding machine is widely known. In injection molding, an injection molding machine in which a screw is disposed in a heating cylinder, and a mold consisting of a male mold and a female mold are used. In a general injection molding, a measuring step (also referred to as a plasticizing measuring step), a clamping step, an injection filling step, a pressure holding and cooling step, and a mold removal step are sequentially performed.

  In the measuring step, a pellet-like molding material (melt molding material) containing a resin as a main component is supplied into the heating cylinder. The molding material is fed toward the tip of the heating cylinder while being melted by the heat from the heating cylinder and the shear frictional heat due to the screw rotation. Then, the molding material is stored between the heating cylinder tip and the nozzle without flowing out of the nozzle. When the storage amount of the molding material increases, the rotating screw is pushed backward according to the storage amount and retreats in the direction opposite to the nozzle. The storage amount of the molding material is measured from the retracted position of the screw. When the screw returns to the predetermined retracted position, the rotation of the screw is stopped and the measurement process is completed.

  Next, the male and female molds are combined and clamped, and then the nozzle at the tip of the heating cylinder is connected to the gate of the mold (clamping process). Then, while the rotation is stopped, the screw is moved toward the tip end of the heating cylinder to inject and fill the molten molding material into the cavity in the mold at a high pressure (injection filling step). The pressure is maintained while the nozzle is pressed against the gate of the mold so that the molding material in the mold is maintained at a predetermined pressure even after the injection and filling (pressure holding step). Thereafter, the mold is cooled to solidify the molded product (cooling step). Finally, the mold is separated into a male mold and a female mold, and the molded product is taken out (mold removal step).

  At this time, the dimensional accuracy as a determination factor of the quality of the finished molded product, and the presence or absence of shrinkage, warpage, dents and voids, or the strength, etc. are the condition of the molding material (pressure, temperature, etc.) before injection into the cavity. It is known to have a correlation. Thus, conventionally, for example, a pressure sensor is fixed to the cylinder so that the pressure of the nozzle portion can be detected so that the finished injection molded product has a desired quality, and molding in the nozzle portion before injection into the cavity in the mold There is a technique of detecting the pressure of a material and controlling the screw movement amount and the like so that the pressure becomes a predetermined value (see FIG. 1 of Patent Document 1 and FIG. 1 of Patent Document 2). Further, there is a technology in which a temperature sensor is fixed to the cylinder to detect the temperature of the molding material in the vicinity of the inner circumferential surface of the cylinder and to control the heater so that the temperature becomes a predetermined value (Patent Document 3, FIG. 1 reference).

Patent No. 401378 Patent No. 5781471 gazette JP 2017-170800 A

  However, even if the pressure and temperature of the molding material are controlled to the desired values using these methods, the variation in the quality of the finished injection molded product is not small, and at present, a satisfactory yield has not been obtained. is there. The reason for this is that, at present, the pressure and temperature are measured only at locations close to the cylinder, so the measurement locations are limited, and it is not possible to sufficiently grasp the overall condition of the molding material before injection molding. Is considered as one of the causes. However, as a place other than the vicinity of the cylinder, for example, when the sensor is attached to the screw in order to grasp the state of the molding material in the vicinity of the screw, the screw is a rotating member. For this reason, there is a problem that it is difficult to establish wiring from the sensor.

  An object of the present invention is to provide an injection molding machine in which a desired quality is stably obtained for a finished injection molded product by controlling the state of a molding material before injection into a cavity.

  In the injection molding machine according to the present invention, the thermoplastic melt-forming material is supplied to the space on the inner peripheral side, and the space on the inner peripheral side and the external space are provided at the first end portion which is one end in the axial direction. A cylindrical heating cylinder having a nozzle for communicating between the two, and a screw rotatably and axially movable in an axial direction in the space of the heating cylinder and having a hole formed therein A heater provided in a heating area formed on the first end side of the heating cylinder in the axial direction and heating the molten molding material supplied into the space; and a screw disposed in the screw; A sensor that detects an index indicating the state of the molten molding material located in the heating area and outputs an output signal of the index; and a non-heating area formed outside the heating area in the axial direction, the sensor Respect of the output signal, and a control unit for executing a predetermined processing, is provided in the bore of the screw, and a connection line for electrically connecting the sensor and the control unit.

  According to the injection molding machine in the above aspect, before injection molding, a sensor that detects an index of the state of the melt-formed material located in the heating area is disposed in the screw, and the control unit is disposed in the non-heating area. The control unit is electrically connected to the sensor via a connection line arranged in the bore of the screw. In addition, the control unit can execute predetermined processing such as wireless transmission on the output signal of the sensor. Thus, by disposing the sensor in the screw and arranging the control unit which can not be disposed in the high temperature region (heating region) because of the electronic circuit, predetermined processing can be performed on the output signal of the sensor . As a result, the output signal output from the sensor can be used, so that the state of the melt-formed material in the vicinity of the screw, which could not be measured by the prior art, can be grasped. I can understand the status. In addition, since the state of the melt-molded material can be controlled based on the grasped state, the quality of the injection-molded article can be stably improved.

It is a sectional view of an injection molding machine concerning an embodiment. It is an external view of FIG. It is an expanded sectional view of the screw part in FIG. It is an enlarged view of the front-end | tip part of the screw in FIG. It is an enlarged view of the rear part of the screw in FIG. It is a flow chart explaining operation of an injection molding machine. It is a figure corresponding to FIG. 4 explaining the modification 1 of 1st embodiment. It is a figure corresponding to FIG. 5 which illustrates 2nd embodiment. It is a figure explaining a third embodiment.

(1. First embodiment)
The injection molding machine 1 of the first embodiment will be described with reference to FIGS. 1 to 5. FIG. 1 is a side view of the internal structure of an injection molding machine 1 on which the injection device 10 of the first embodiment is mounted. The X direction, the Y direction and the Z direction are directions perpendicular to each other, as shown in FIG.

  As shown in FIG. 1, the injection molding machine 1 includes a support Fr, an injection device 10, and a control device 100. The support Fr supports the injection device 10 so as to be movable back and forth in the X-axis direction. Thus, the injection device 10 can be advanced and retracted with respect to the mold apparatus M. When the injection device 10 advances (direction toward the left in FIG. 1), the nozzle 22 of the injection device 10 that opens to the outside is connected to the mold device M (corresponding to a mold).

  Then, a molding material (corresponding to a melt molding material, hereinafter referred to as a melt molding material PT) is injected from the nozzle 22, and the cavity CA, which is a space in the mold apparatus M, is filled with the melt molding material PT. Thereafter, the molten molded material PT filled in the cavity CA is cooled and solidified to obtain an injection molded article. Melt molding material PT is a thermoplastic resin material. As the melt molding material PT, POM (polyacetal), PA (polyamide), PC (polycarbonate), PEEK (peak), PAI (polyamide imide), PPS (polyphenylene sulfide) or the like can be applied.

  The injection device 10 includes a heating cylinder 20, a screw 30, a heater 40, and a drive device 50, each of which is a first sensor 60 (corresponding to a sensor) and a second sensor 70 (corresponding to a sensor) shown in FIGS. The control units 80 and 81, the connection lines 90 and 91, and the like are provided. The first sensor 60 is a sensor that detects the temperature T (corresponding to an index, not shown) of the molten molding material PT. The second sensor 70 is a sensor that detects a pressure P (corresponding to an index, not shown) of the molten molding material PT. In addition, not only the said aspect but a sensor may be provided only with the 1st sensor 60, and only the 2nd sensor 70 may be provided.

  The heating cylinder 20 is a cylindrical metal member for heating the melt molding material PT which is a thermoplastic resin supplied from the supply port 20a to the space on the inner circumferential side. The heating cylinder 20 is provided with the above-mentioned nozzle 22 which makes the space between the inner peripheral side communicate with the external space at the first end 21 which is one end in the axial direction. The opening of the nozzle 22 is pressed against the mold apparatus M. In addition, hereinafter, in the case of the axial direction, the axial direction of the heating cylinder 20 is referred to.

  The supply port 20 a is formed at the rear of the heating cylinder 20. In the heating cylinder 20, a heater 40 such as a band heater is provided in front of the supply port 20a. In the present embodiment, on the first end 21 side of the heating cylinder 20, three heaters 40 are provided at regular intervals in the axial direction. However, the present invention is not limited to this aspect, and the heaters may be provided further forward than the three heaters 40. The heater 40 is controlled by the temperature control device 106 provided in the control device 100 such that the temperature T of the melt-formed material PT detected by the first sensor 60 described later in detail becomes a desired temperature T1 (not shown).

  Thereby, the molten molding material PT supplied into the space on the inner peripheral side of the heating cylinder 20 is heated and melted through the heating cylinder 20. In the present embodiment, a region of the heating cylinder 20 in which the heater 40 is provided in the axial direction is referred to as a heating region HAr (see FIGS. 1 to 3).

  Further, as shown in FIGS. 1 to 3, in the axial direction, a region opposite to the nozzle 22 and not formed by the heater 40 formed outside the “heated region HAr” is referred to as “non-heated region NHAr”. Name. In the “non-heating area NHAr”, the internal temperature of the heating cylinder 20 is not high and is close to the normal temperature.

  Although nothing is provided on the outer periphery of the heating cylinder 20 in the “non-heating area NHAr” in the present embodiment, a cooling device may be provided on the outer periphery of the heating cylinder 20 to cool the heating cylinder 20. Thereby, the internal temperature of the heating cylinder 20 in the “non-heating area NHAr” can be reliably lowered.

  The screw 30 is disposed rotatably in the axial direction of the screw 30 and movable in the axial direction in the space of the heating cylinder 20. Further, as shown in FIG. 3 and FIG. 4, the screw 30 is formed with a hole 31 extending in the axial direction inside. The hole 31 includes an opening 31 a at the tip of the screw 30 that opens toward the first end 21 of the heating cylinder 20. The hole 31 also has a bottom surface 31 b (see FIG. 5) at the rear end of the screw 30.

  That is, the hole 31 is a bottomed hole having an opening at only one side. However, the present invention is not limited to this mode, and the hole 31 may be penetrated toward the rear without providing the bottom surface 31 b. The first sensor 60, the second sensor 70, the control units 80 and 81, the connecting wires 90 and 91, and the connecting wires 90 and 91 are fixed in the holes 31 of the screw 30, as shown in FIGS. And the like. The first sensor 60, the second sensor 70, the control units 80 and 81, the connection lines 90 and 91, and the fixing member 92 for fixing the connection lines 90 and 91 will be described in detail later.

  The drive device 50 shown in FIG. 1 and FIG. 2 is a device that causes the screw 30 to rotate about an axis at a desired number of rotations and to move the screw 30 in the axial direction by a desired movement amount. As shown in FIGS. 1 and 2, the drive device 50 includes a rotary feed motor 51 for rotating the screw 30 and a linear feed motor 53 for moving the screw 30 in the axial direction.

  As shown in FIG. 1, the rotary feed motor 51 is fixed to the rear support member 55 together with a bearing holder 54 that holds a bearing Brg that rotatably supports the output shaft 52 of the rotary feed motor 51. The rear sliding member 56 to which the rear support member 55 is fixed slides along the guide Gd at the rear of the front sliding member 57.

  The output shaft 52 of the rotary feed motor 51 is disposed on the same straight line as the axis of the screw 30. The output shaft 52 of the rotary feed motor 51 has a fitting portion 58 for fitting the extension shaft of the screw 30 in front of the bearing Brg. The fitting portion 58 has an insertion hole into which the extension shaft of the screw 30 is inserted, and the insertion hole has an inner diameter larger than the outer diameter of the extension shaft of the screw 30.

  The linear feed motor 53 advances and retracts the screw 30 in the axial direction. The linear feed motor 53 is fixed to the front support member 59 as shown in FIG. The rotational movement of the linear feed motor 53 is converted by the ball screw mechanism 151 into linear movement of the rear support member 55 relative to the front support member 59.

  The ball screw mechanism 151 has a ball screw shaft 152 and a ball screw nut 153 screwed to the ball screw shaft 152. As shown in FIG. 2, the ball screw shaft 152 is connected to the output shaft of the linear feed motor 53, and the ball screw nut 153 drives the linear feed motor 53 fixed to the rear support member 55 to rotate the output shaft. The ball screw shaft 152 rotates and the ball screw nut 153 advances and retracts. Then, as the ball screw nut 153 moves forward and backward, the rear support member 55 and the screw 30 move forward and backward.

  Moreover, in this embodiment, although the screw 30 was advanced / retracted by the action | operation of the linear feed motor 53, it does not restrict to this aspect. Alternatively, a piston and a cylinder may be provided at the rear end of the screw 30, and the screw 30 may be advanced and retracted by controlling the pressure of air supplied into the cylinder.

  As shown in FIGS. 1 and 2, the control device 100 includes a central processing unit (CPU) 101, a storage medium 102 such as a memory, an input interface (input I / F) 103, and an output interface (output I / F). And a temperature control unit 106 for controlling the temperature of the heater 40, and a drive control unit 107 for controlling the operation of the drive unit 50. The temperature control device 106 and the drive control device 107 are provided in the CPU 101. The control device 100 performs various controls by causing the CPU 101 to execute a program stored in the storage medium 102.

  Further, the control device 100 receives a signal from the outside (including the receiver 82) at the input interface 103, and transmits a signal to the outside (the driving device 50, the heater 40, etc.) at the output interface 104.

(2. Regarding the configuration in the hole 31 of the screw 30)
Next, a fixing member for fixing the first sensor 60, the second sensor 70, the control units 80 and 81, the connecting wires 90 and 91, and the connecting wires 90 and 91 disposed in the holes 31 and 31 of the screw 30 described above 92 will be described in detail.

  The opening 31a of the hole 31 shown in FIGS. 3 and 4 is located in the “heating area HAr” at least in the state where the screw 30 is retracted most in the axial direction (see FIG. 3). The control units 80 and 81 disposed in the vicinity of the bottom surface 31 b shown in FIGS. 3 and 5 are always positioned in the “non-heating area NHAr” regardless of the position of the screw 30 in the axial direction. Since the control units 80 and 81 are disposed in the “non-heating area NHAr” which is a temperature area near the normal temperature, even if they have an electronic circuit, they can operate satisfactorily.

  The first sensor 60 is a temperature sensor that detects the temperature T of the melt-formed material PT stored in the storage portion Q, which is a space portion in front of the screw 30, in particular, the temperature T in the vicinity of the screw 30. The first sensor 60 may be any type of sensor, for example, a thermocouple, a thermistor, a resistance temperature detector, or the like. The first sensor 60 is disposed at the tip of the screw 30. Specifically, the first sensor 60 is fixed to the inner peripheral surface of the opening 31 a provided at the tip of the screw 30.

  The first sensor 60 is positioned in the heating area HAr at least in a state where the melt molding material PT is stored in a predetermined amount in the storage portion Q and the screw 30 is thus retracted in the axial direction. The first sensor 60 may be disposed so as to always be located in the heating area HAr regardless of the position of the screw 30 in the axial direction.

  The first sensor 60 is fixed in a state in which the detection unit 61 at the front end faces the storage unit Q side, and the detection unit 61 detects the temperature T (index) of the molten molding material PT stored in the storage unit Q. The output signal S1 of the temperature T (index) detected by the first sensor 60 is transmitted to the control unit 80 via the connection line 90. The connection line 90 is a conductive line that electrically connects the first sensor 60 and the control unit 80. The connecting wire 90 is also disposed in the hole 31 of the screw 30.

  The control unit 80 is disposed near the bottom surface 31 b as described above. At this time, the control unit 80 is always located in the "non-heating area NHAr" formed outside the "heating area" in the axial direction. Specifically, the control unit 80 is disposed near the bottom surface 31 b in the hole 31 of the screw 30 and fixed to the inner circumferential surface of the hole 31.

  The control unit 80 performs a predetermined process on the output signal S1 of the temperature T detected by the first sensor 60. Here, the predetermined process refers to wireless transmission, and the control unit 80 is a wireless transmitter. That is, after receiving the output signal S1 from the first sensor 60 via the connection line 90, the control unit 80 performs the predetermined process on the output signal S1 toward the receiver 82 disposed at a position different from the screw 30. Transmit by wireless. The receiver 82 is provided near the control device 100. Then, the output signal S1 received by the receiver 82 is input to the control device 100.

  The fixing member 92 is filled in the space inside the hole 31 of the screw 30 and mainly fixes the connection line 90. As a result, when the screw 30 rotates, the connecting wire 90 can be prevented from being shaken by the centrifugal force caused by the rotation, and noise can be added to the output signal S1. In addition, the fixing member 92 is interposed between the connection wire 90 and the inner circumferential surface of the hole 31 so as to separate the connection wire 90 from the inner circumferential surface of the hole 31. Thereby, the influence of the heat from the inner peripheral surface of the hole 31 to the connection line 90 disposed in the “heating area HAr” portion can be effectively suppressed. However, the present invention is not limited to this embodiment, and the fixing member 92 does not intervene between the connection wire 90 and the inner peripheral surface of the hole 31, but in a state where the connection wire 90 contacts the inner peripheral surface of the hole 31. It may be filled. This is also enough to use.

  The fixing member 92 is, for example, a thermosetting resin. As a thermosetting resin, a phenol resin, a melamine resin, an epoxy resin etc. are applicable, for example. Further, in the present embodiment, the fixing member 92 is filled so as to also cover the first sensor 60 (but excluding the detection unit 61) and the outer periphery of the control unit 80. However, the present invention is not limited to this aspect, and the fixing member 92 may not cover the outer periphery of the first sensor 60 and the control unit 80.

  The second sensor 70 shown in FIGS. 3 and 4 detects the pressure P of the melt-formed material PT stored in the front storage portion Q of the screw 30, particularly the pressure P near the screw 30 by the detection portion 71 of the tip. It is a sensor. The second sensor 70 may be any type of sensor, and for example, a resistance wire type, a capacitance type, a mechanical type or the like can be applied. Similar to the first sensor 60, the second sensor 70 is disposed at the tip of the screw 30. Specifically, the second sensor 70 is fixed to the inner peripheral surface of the opening 31 a provided at the tip of the screw 30 (see FIGS. 3 and 4).

  The second sensor 70, the connection line 91, the arrangement of the control unit 81 electrically connected to the second sensor 70 via the connection line 91, and the filling of the fixing member 92 for fixing the connection line 91, respectively. The control unit 80 (corresponding to the control unit 81), the connection line 90 (corresponding to the connection line 91), and the fixing member 92, which are the same as the first sensor 60 (corresponding to the second sensor 70) described above; Detailed description is omitted.

  That is, regarding each arrangement of the second sensor 70, the control unit 81 and the connection line 91, the first sensor 60 is replaced with the second sensor 70, the control unit 80 is replaced with the control unit 81, and the connection line 90 is connected 91 It should be read as Furthermore, the temperature T may be read as the pressure P, and the output signal S1 may be read as the output signal S2.

  In addition, in the above, although the 1st sensor 60 and the 2nd sensor 70 were demonstrated as what is fixed to the internal peripheral surface of the opening part 31a of the hole 31, it does not restrict to this aspect. When the thermosetting resin is filled in the holes 31, the resin is solidified between the first sensor 60 and the second sensor 70 and the inner circumferential surface to solidify the first sensor 60 and the second sensor 70. And the inner circumferential surface may be fixed in a separated state. The control units 80 and 81 are the same.

  In the above, it has been described that the hole 31 has the opening 31a at the tip of the screw 30, and the first sensor 60 and the second sensor 70 are fixed to the inner peripheral surface of the opening 31a. However, it is not limited to this aspect. The hole 31 may not have the opening 31 a at the tip. That is, the hole 31 may have a bottom surface at the tip of the screw 30, and the first sensor 60 and the second sensor 70 may be embedded in the bottom surface. In this case, the first sensor 60 and the second sensor 70 are embedded and arranged on the bottom surface so that the detection portions 61 and 71 can detect the temperature T and the pressure P of the melt-formed material PT stored in the storage portion Q. .

(3. Operation)
The control device 100 controls a measurement step S10, an index measurement step S20, a feedback step S30, a filling step S40, a pressure holding step S50, a cooling step S60, and the like shown in the flowchart of FIG. First, the measurement process S10 will be described. The measuring step S10 is a step of storing a predetermined amount of the melt-formed material PT to be injected into the cavity CA of the mold apparatus M in a reservoir Q formed between the front portion of the screw 30 and the heating cylinder 20. The description will be made on the premise that the molten molding material PT is not stored in the storage portion Q at the start of the measurement step S10. Further, in the measuring step S10, the nozzle 22 is controlled to be in the closed state by a predetermined means.

  In the measuring step S10, the rotary feed motor 51 is controlled by the drive control device 107 of the control device 100 to rotate the screw 30 about the axis (see FIG. 1). As a result, the molten molding material PT is fed forward along the spiral groove 32 of the screw 30 (see arrow A in FIG. 3). At this time, when the molten molding material PT is supplied from the supply port 20a into the space in the "non-heated area NHAr" of the heating cylinder 20, the molten molding material PT is a pellet-like solid.

  Thereafter, the molten material PT moves to the “heating area HAr” while being fed forward with the rotation of the screw 30. As a result, the molten molding material PT is gradually melted and becomes liquid by the heat of the heating cylinder 20 heated by the heater 40.

  When the screw 30 further rotates, the liquid melt-forming material PT is further fed to the front of the screw 30 and gradually stored in the reservoir Q. And if the internal pressure of the storage part Q rises, the screw 30 will be retracted according to the rise of the internal pressure (refer arrow B of FIG. 3). Whether or not the predetermined amount of the melt-formed material PT is stored in the storage portion Q is determined by, for example, the number of rotations of the screw 30.

  When the number of rotations of the screw 30 reaches a predetermined value, it is determined that a predetermined amount of the melt-formed material PT is stored in the storage portion Q. The rotational speed of the screw 30 is detected, for example, using the encoder 51 a of the rotary feed motor 51. The encoder 51a transmits a signal indicating the detection result to the control device 100. However, the present invention is not limited to the above embodiment, and whether or not the predetermined amount of the melt-formed material PT is stored in the storage portion Q may be performed based on the retracted position of the screw 30 detected by a predetermined means.

  In the index measurement step S20, in a state where a predetermined amount of the melt-formed material PT is stored in the storage portion Q, each of the detection portions 61, 61 of the first sensor 60 and the second sensor 70 Temperature T (index) and pressure P (index) are detected.

  The first sensor 60 and the second sensor 70 transmit the output signal S1 (T) and the output signal S2 (P) to the control units 80 and 81 via the connection lines 90 and 91, respectively. At this time, the connecting wires 90 and 91 are fixed so as not to be relatively movable with respect to the inner peripheral surface of the hole 31 in a state in which the outer periphery is completely surrounded by the fixing member 92 respectively. For this reason, even if the screw 30 rotates, the connecting wires 90 and 91 are not shaken by centrifugal force. Therefore, there is no possibility that noise is added to the output signal S1 and the output signal S2 by the rotation of the screw 30.

  The control units 80 and 81 to which the output signal S1 and the output signal S2 are input respectively direct the output signal S1 and the output signal S2 to the receiving units 82a and 82b included in the receiver 82 provided outside the injection device 10. A wireless transmission process, which is a predetermined process, is performed. The receiver 82 transmits the received output signals S1 and S2 to the control device 100.

  At this time, as described above, the control units 80 and 81 are always located in the “non-heating area NHAr” formed outside the “heating area” in the axial direction. For this reason, since the control units 80 and 81 are not exposed to high temperature, even if they have electronic circuits, the transmission function is well maintained without failure.

  Next, in the feedback step S30, first, the CPU 101 inputs the output signal S1 (temperature T) and the output signal S2 (pressure P) that are input, and a master signal value MS1 (temperature not shown) stored in advance in the storage medium 102. T1) and the master signal value MS2 (pressure P1) are compared.

  Then, when the output signal S1 (temperature T) does not match the master signal value MS1 (temperature T1), the CPU 101 calculates a difference and transmits the difference to the temperature control device 106. The temperature control device 106 controls the heater 40 (for temperature control) so that the output signal S1 (temperature T) matches the master signal value MS1 (temperature T1) based on the transmitted difference.

  When the output signal S2 (pressure P) does not match MS2 (pressure P1), the CPU 101 calculates a difference and transmits the difference to the drive control device 107. The drive control device 107 controls the linear feed motor 53 (for pressure control) of the drive device 50 so that the output signal S2 (pressure P) becomes MS2 (pressure P1) based on the transmitted difference, and advances and retracts the screw 30. Let

  In the above, the master signal values MS1 (temperature T1) and MS2 (pressure P1) are the quality data (quality information) of the injection molded product manufactured (molded) before the injection molded product manufactured (molded) this time. And the output data S1 and S2 at the time of injection molding of the injection molded product for which the quality data is measured, which are derived based on corresponding data, and are stored in the storage medium 102.

  Also, at this time, the quality data (quality information) refers to the dimensional accuracy of the completed injection-molded product, the presence or absence of shrinkage, warpage, depressions and voids, or the strength. These quality information has a correlation with the state (pressure, temperature, etc.) of the molten molding material PT before injection into the cavity CA.

  In the above, the master signal values MS1 (temperature T1) and MS2 (pressure P1) may be set in any manner. For example, as conventionally done, it may be set to be equivalent to the output signals S1 and S2 corresponding to the injection molded product of the acceptable product. Further, as another method, a large number of corresponding data may be acquired and calculated and processed by, for example, AI (Artificial Intelligence) using a large number of stored corresponding data.

  Next, the filling step S40 will be described. By control of the heater 40 and the linear feed motor 53, it is confirmed that the output signal S1 (temperature T) and the output signal S2 (pressure P) coincide with the master signal values MS1 (temperature T1) and MS2 (pressure P1). And, in the filling step S40, the CPU 101 controls the nozzle 22 in the release state. Thereafter, the linear feed motor 53 is driven to move the screw 30 forward at a set speed (see arrow C in FIG. 3). As a result, the melt molding material PT, which is stored in the storage portion Q by a predetermined amount and controlled to a suitable temperature T1 and pressure P1, is ejected from the nozzle 22 and filled in the cavity CA of the mold apparatus M.

  The position and speed of the screw 30 are detected by using, for example, an encoder 53 a provided to the linear feed motor 53. The encoder 53a detects the rotation of the linear feed motor 53, and transmits a signal indicating the detection result to the control device 100. When the position of the screw 30 reaches the set position, the switching from the filling step S40 to the pressure holding step S50 is performed. The set speed of the screw 30 may be changed according to the position of the screw 30, cycle time, and the like.

  In the pressure holding step S50, the linear feed motor 53 is driven to push the screw 30 forward at a set pressure, and pressure is applied to the molten molding material PT filled in the cavity CA space in the mold apparatus M. As a result, the molten molding material PT can be replenished due to the shortage due to the cooling shrinkage. The pressure of the molten molding material PT is detected using, for example, a load detector 154.

  In the pressure holding step S50, the molten molding material PT in the cavity CA space is gradually cooled, and at the completion of the pressure holding step, the inlet of the cavity CA space is blocked with the solidified molten molding material PT. This state is called a gate seal, which prevents the backflow of the molten molding material PT from the cavity CA space. After completion of the pressure holding step S50, the cooling step S60 is started. In the cooling step S60, solidification of the molten molding material PT in the cavity CA space is performed. In order to shorten the molding cycle, the measurement step S10 may be performed in parallel during the cooling step S60.

  In the above embodiment, the received output signals S1 and S2 are transmitted to the control device 100 to perform various processing. However, it is not limited to this aspect. The receiver 82 may transmit the received output signals S1 and S2 to the PC, and store data of the output signals S1 and S2 in the PC. Then, various processes may be performed in the PC to generate master signal values MS1 (temperature T1) and MS2 (pressure P1), and thereafter, may be transmitted to the control device 100.

(Effect according to the embodiment)
According to the above-described embodiment, the injection molding machine 1 is supplied with the thermoplastic melt-forming material PT in the space on the inner peripheral side, and the inner peripheral side at the first end 21 which is one end in the axial direction. And a cylindrical heating cylinder 20 provided with a nozzle 22 for communicating between the space in FIG. 2 and the external space, and the space of the heating cylinder 20 rotatably and axially movably disposed about the axis, A screw 30 in which a hole 31 is formed, and a heater 40 provided in a heating area HAr formed on the first end side of the heating cylinder 20 in the axial direction and heating the molten molding material PT supplied into the space A first sensor 60 and a second sensor 70 (sensors) which are disposed in the screw 30 and detect an index indicating the state of the melt-formed material PT located in the heating area HAr and output an output signal of the index; A control unit 80, 81 disposed in the non-heating area NHAr formed outside the thermal area HAr and performing predetermined processing on output signals S1, S2 of the first sensor 60 and the second sensor 70 (sensor) , Connection wires 90 and 91 provided in the holes 31 of the screw 30 and electrically connecting the first sensor 60 and the second sensor 70 to the control units 80 and 81.

  Thus, before injection molding, the first sensor 60 and the second sensor 70 (sensor) for detecting the index of the state of the melt-formed material PT located in the heating area HAr are disposed in the screw 30, and the non-heating area NHAr Control units 80 and 81 are arranged. The control units 80 and 81 are electrically connected to the first sensor 60 and the second sensor 70 (sensors) via connection wires 90 and 91 disposed in the holes 31 of the screw 30.

  Further, the control units 80 and 81 can execute predetermined processing such as wireless transmission with respect to the output signals S1 and S2 of the first sensor 60 and the second sensor 70 (sensor). Thus, since the first sensor 60 and the second sensor 70 (sensor) are disposed in the screw 30 and the electronic circuit is provided, the control units 80 and 81 which can not be disposed in the high temperature region (heating region HAr) are in the low temperature region (non-heating region By arranging in NHAr, predetermined processing can be performed on output signals of the first sensor 60 and the second sensor 70 (sensor).

  As a result, since the output signals S1 and S2 output from the first sensor 60 and the second sensor 70 (sensors) can be used, the state of the melt-formed material PT in the vicinity of the screw which could not be measured by the prior art can be grasped As a result, the state of the melt-formed material PT before injection molding can be grasped more accurately. Further, since the state of the melt-molded material PT can be controlled based on the grasped state, the quality of the injection-molded product can also be improved.

(5. Other)
(5-1. Modified Example 1)
In the first embodiment, the first sensor 60 and the second sensor 70 are fixed to the inner circumferential surface (inner side) of the opening 31 a of the hole 31 provided in the screw 30. However, it is not limited to this aspect. As a first modification, as shown in FIG. 7, the first sensor 60 and the second sensor 70 may be provided on the inner peripheral surface of the opening 31 c that opens in the side surface of the heating cylinder 20. At this time, as shown in FIG. 7, the opening 31c is preferably opened toward a part of the storage portion Q, but it may be formed to open in the spiral groove 32 of the screw 30 in the axial direction. Good. The other parts are the same as in the first embodiment. Also by this, since an index (temperature, pressure, etc.) of a portion which has not been measured can be measured, a corresponding effect can be obtained.

(5-2. Second embodiment)
Next, an injection molding machine 200 of the second embodiment will be described. In the injection molding machine 1 of the first embodiment, the control units 80 and 81 are wireless transmitters, and the predetermined processing performed by the control units 80 and 81 is wireless transmission of the output signals S1 and S2.

  However, in the second embodiment, the control units 280 and 281 (see FIG. 8) may simultaneously include the control devices 280a and 281a as well as the wireless transmitters. That is, the control units 280 and 281 are disposed in the holes 31 of the screw 30, and acquire (receive) the output signals S1 and S2 through the connection lines 90 and 91. After that, as predetermined processing, the control units 280 and 281 output control signals to the drive control device 107 of the screw 30 and the temperature control device 106 of the heater 40 arranged at positions different from the screw 30 as output signals S1 and S2. , And may be transmitted to the receiver 82 from the radios 280b and 281b. Also by this, the same effect as the first embodiment can be expected.

  In addition, in the said embodiment, although the sensor (two or more) of the 1st sensor 60 and the 2nd sensor 70 was arrange | positioned, it does not restrict to this aspect. The sensor may be provided only by one of the first sensor 60 and the second sensor 70, or three or more (plural) sensors. When three or more are provided, the index to be measured may be other than temperature and pressure.

  In the above embodiment, the fixing member 92 for fixing the connecting wires 90 and 91 is filled in the hole 31 of the screw 30. However, it is not limited to this aspect. The fixing member 92 may be eliminated. A corresponding effect can be obtained also by this.

(5-3. Third embodiment)
Next, an injection molding machine 300 of the third embodiment will be described. In the third embodiment, a case where the injection molding machine 300 has only the first sensor 60 will be described. In the third embodiment, unlike in the first and second embodiments, the control unit 380 (see FIG. 9) is not in the hole 31 of the screw 30 but at a position different from the screw 30 in the radial direction outside of the screw 30. Will be placed on the The output signal S1 is then transmitted to the control unit 380 via the connecting line 90 and the known slip ring 381.

  After receiving the output signal S1, the control unit 380 outputs each control signal to the drive control device 107 of the screw 30 and the temperature control device 106 of the heater 40 which are disposed at a position different from the screw 30 as a predetermined process. Generate based on and send by wire or wireless. However, the present invention is not limited to this aspect, and as in the first embodiment, the control unit 380 may be a simple transmitter without a control device. Also by these, the same effect as the first and second embodiments can be expected. The slip ring 381 is a known technique for bringing the rotating body and the fixed body into conduction. Therefore, the detailed description is omitted.

  1,200,300 injection molding machine 10 injection device 20 heating cylinder 21 first end 22 nozzle 30 screw 31 hole 31a opening 40 heater 50 Drive device, 51; Rotary feed motor, 53; Linear feed motor, 60; First sensor, 70; Second sensor, 80, 81, 280, 281, 380; Control unit, 82; Receiver, 90, 91; Wire; 92; fixing member, 100; control device, 106; temperature control device, 107; drive control device, 381; slip ring, CA; cavity, HAr; heating area, M; mold device (mold), NHAr; Unheated area, P, P1; pressure, PT; melt molding material, Q; reservoir, S1, S2; output signal, T, T1; temperature.

Claims (10)

A thermoplastic melt-forming material is supplied to the space on the inner circumferential side, and the first end, which is one end in the axial direction, has a nozzle that causes the space on the inner circumferential side to communicate with the outer space. A cylindrical heating cylinder,
A screw rotatably and axially movably disposed about the axis in the space of the heating cylinder and having a hole formed therein;
A heater, provided in a heating area formed on the first end side of the heating cylinder in the axial direction, for heating the molten molding material supplied into the space;
A sensor disposed in the screw, which detects an index indicating the state of the melt-formed material located in the heating area, and outputs an output signal of the index;
A control unit disposed in a non-heating area formed outside the heating area in the axial direction and performing a predetermined process on the output signal of the sensor;
A connection line provided in the hole of the screw and electrically connecting the sensor and the control unit;
, An injection molding machine.   The injection molding machine according to claim 1, wherein the sensor is disposed at a tip of the screw. The hole has an opening at the tip end of the screw that opens toward the first end side of the heating cylinder,
The injection molding machine according to claim 2, wherein the sensor is disposed inside the opening.   The control unit is disposed in the hole of the screw, and after receiving the output signal via the connection line, the output signal is transmitted to a receiver disposed at a position different from the screw as the predetermined processing. The injection molding machine according to any one of claims 1 to 3, wherein the wireless transmission is performed wirelessly. A drive device controlled by a drive control device for rotationally operating the screw about the axis and moving the screw in the axial direction;
A temperature control device for controlling the heater;
The control unit is disposed in the hole of the screw, and after receiving the output signal via the connection line, the drive control of the screw disposed at a position different from the screw as the predetermined processing. The injection molding machine according to any one of claims 1 to 3, wherein control signals for the device and the temperature control device of the heater are generated based on the output signal and wirelessly transmitted. A drive device controlled by a drive control device for rotationally operating the screw about the axis and moving the screw in the axial direction;
A temperature control device for controlling the heater;
The control unit is disposed at a position different from the screw, and after receiving the output signal through the connection line and the slip ring, the control unit is disposed at a position different from the screw as the predetermined process. The injection molding machine according to any one of claims 1 to 3, wherein control signals for the temperature control device of the drive control device and the heater are generated and transmitted based on the output signal.   The injection molding machine according to any one of claims 1 to 6, wherein a plurality of the sensors are arranged.   The injection molding machine according to any one of claims 1 to 7, wherein a fixing member for fixing the connection wire is filled in the hole of the screw.   The injection molding machine according to claim 8, wherein the connection line is fixed by being separated from the inner circumferential surface of the hole by the fixing member. The screw is based on the corresponding data of the quality information of an injection molded product obtained by injection molding the melt molding material from the nozzle into a cavity in a mold and the output signal at the time of injection molding of the molded injection molded product. The injection molding machine according to claim 5 or 6, wherein the temperature control device of the drive control device and the heater is controlled to mold the injection molded product.

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