TW201711825A - Injection molding machine capable of stabilizing the quality of a molded article - Google Patents

Abstract

The present invention provides an injection molding machine capable of stabilizing the quality of a molded article. The injection molding machine comprises: a detector for detecting the flow of molding material in a mold device; and a control device for controlling the compression operation of compressing the molding material in the cavity space in the mold device according to the detection results of the detector.

Description

Injection molding machine

The present application claims priority based on Japanese Patent Application No. 2015-191823, filed on Sep. 29, 2015. The entire contents of this Japanese application are incorporated herein by reference.

The present invention relates to an injection molding machine.

In the injection molding machine described in Patent Document 1, the first injection process of ejecting the molten resin accumulated in the tip end side of the screw into the mold is performed by advancing the screw in the heating cylinder, and the process is started in the middle of the one-shot injection process. A compression process that imparts a compressive pressure to the resin in the mold. The injection molding machine starts the compression process when the measured advancement distance of the screw reaches a preset set value.

(previous technical literature) (Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 2002-113753

Conventionally, the influence of fluctuations in the injection molding process in a process other than the compression process may be expanded by the compression process, and the variation in the quality of the molded article may become large.

The present invention has been made in view of the above circumstances, and a main object thereof is to provide an injection molding machine capable of stabilizing the quality of a molded article.

In order to solve the above problems, an injection molding machine is provided according to an aspect of the present invention, comprising: a detector for detecting a flow of a molding material in a mold device; and a control device for controlling the mold device according to a detection result of the detector The compression action of the aforementioned molding material is compressed in the cavity space inside.

According to an aspect of the invention, an injection molding machine capable of stabilizing the quality of a molded article is provided.

30‧‧‧Molding device

32‧‧‧Fixed mode

33‧‧‧ movable mold

34‧‧‧ cavity space

36‧‧‧Compressed components

37‧‧‧Detector

40‧‧‧Injection device

41‧‧‧Cylinder block

42‧‧‧Nozzles

43‧‧‧ screw

50‧‧‧Intermediate device

60‧‧‧Ejecting device

90‧‧‧Control device

Fig. 1 is a view showing a state at the time of completion of mold opening of the injection molding machine according to the embodiment.

Fig. 2 is a view showing a state at the time of mold clamping of the injection molding machine of the embodiment.

Figure 3 is a view showing the compression operation of the injection molding machine of one embodiment. A diagram of the state within the mold device before the start.

Fig. 4 is a view showing a state in the mold device after completion of the compression operation of the injection molding machine according to the embodiment.

Fig. 5 is a view showing a state at the time of mold clamping of the injection molding machine according to the modification.

In the following, the embodiments of the present invention will be described with reference to the accompanying drawings, and the same or corresponding components are designated by the same or corresponding components, and the description is omitted.

Fig. 1 is a view showing a state at the time of completion of mold opening of the injection molding machine according to the embodiment. Fig. 2 is a view showing a state at the time of mold clamping of the injection molding machine of the embodiment. In the first and second drawings, the flow path indicating the molding material in the mold device 30 is simplified for convenience of explanation.

For example, as shown in FIGS. 1 and 2, the injection molding machine has a frame Fr, a mold clamping device 10, an injection device 40, an intermediate device 50, an ejection device 60, and a control device 90. Further, the intermediate device 50 may be included in the mold device 30 or may not be included in the injection molding machine.

First, the mold clamping device 10, the intermediate device 50, and the ejection device 60 will be described. In the description of the mold clamping device 10 and the like, the moving direction of the movable platen 13 at the time of mold closing (the right direction in the first drawing and the second drawing) is set to the front, and the moving direction of the movable platen 13 at the time of mold opening ( The left direction in the first and second figures is set to the rear.

The mold clamping device 10 performs mold closing, mold clamping, and mold opening of the mold device 30. The mold clamping device 10 has a fixed platen 12, a movable platen 13, a support platen 15, a tie rod 16, a toggle mechanism 20, a mold clamping motor 21, and a motion conversion mechanism 25.

The fixed platen 12 is fixed to the frame Fr. A fixed mold 32 is attached to a surface of the fixed platen 12 that faces the movable platen 13.

The movable platen 13 is freely movable along a guide (for example, a guide rail) 17 laid on the frame Fr, and is movable forward and backward with respect to the fixed platen 12. A movable mold 33 is attached to the surface of the movable platen 13 opposed to the fixed platen 12 through the intermediate device 50.

The mold closing, the mold clamping, and the mold opening are performed by advancing and retracting the movable platen 13 with respect to the fixed platen 12. The mold device 30 is constituted by the fixed mold 32 and the movable mold 33.

The support platen 15 is coupled to the fixed platen 12 with a space therebetween, and is movably placed on the frame Fr in the mold opening and closing direction. In addition, the support platen 15 can also be moved freely along the guides laid on the frame Fr. The guide supporting the pressure plate 15 may be common to the guide 17 of the movable platen 13.

Further, in the present embodiment, the fixed platen 12 is fixed to the frame Fr, and the support platen 15 is movable in the mold opening and closing direction with respect to the frame Fr. However, the support platen 15 may be fixed to the frame Fr, and the fixed platen 12 may be fixed relative to the frame Fr. Move freely along the mold opening and closing direction.

The tie rod 16 connects and fixes the pressure plate 12 and the support pressure plate 15 with a space therebetween. A plurality of root tie rods 16 can be used. Each tie rod 16 is parallel to the mold opening and closing direction and extends in accordance with the mold clamping force. A mold clamping force detector 18 is provided on at least one of the tie bars 16. The clamping force detector 18 can be a strain ritual by the detection system The strain of the rod 16 is used to detect the clamping force.

Further, the mold clamping force detector 18 is not limited to the strain ceremony, and may be a piezoelectric type, a capacitive type, a hydraulic type, an electromagnetic type or the like, and the mounting position thereof is not limited to the tie rod 16.

The toggle mechanism 20 is disposed between the movable platen 13 and the support platen 15. The toggle mechanism 20 is composed of a crosshead 20a, a plurality of links 20b, 20c, and the like. One of the links 20b is swingably attached to the movable platen 13, and the other link 20c is swingably attached to the support platen 15. The links 20b and 20c are connected to each other by a pin or the like so as to be expandable and contractible. By advancing and retracting the crosshead 20a, the plurality of links 20b, 20c expand and contract, and the movable platen 13 advances and retracts relative to the support platen 15.

The mold clamping motor 21 is attached to the support platen 15, and the movable platen 13 is advanced and retracted by advancing and retracting the crosshead 20a. Between the mold clamping motor 21 and the crosshead 20a, a motion conversion mechanism 25 that converts the rotational motion of the mold clamping motor 21 into a linear motion and transmits it to the crosshead 20a is provided. The motion converting mechanism 25 is constituted by, for example, a ball screw mechanism. The position and speed of the crosshead 20a are detected by, for example, the encoder 21a of the mold clamping motor 21.

The operation of the mold clamping device 10 is controlled by the control device 90. The control device 90 controls the mold closing process, the mold clamping process, the mold opening process, and the like.

In the mold closing process, the movable platen 13 is advanced by driving the mold clamping motor 21, thereby bringing the movable mold 33 into contact with the fixed mold 32. A compression member 36 is disposed on the movable mold 33 side, and the compression member 36 is retractable in the mold device 30.

In the mold clamping process, the mold clamping motor 21 is further driven to generate a joint Mold force. At the time of mold clamping, a cavity space 34 is formed between the compression member 36 disposed on the side of the movable mold 33 and the fixed mold 32, and the cavity space 34 is filled with a liquid molding material. Within the cavity space 34, the forming material is compressed by the compression member 36. The molding material in the cavity space 34 is solidified to be a molded article.

In the mold opening process, the movable mold plate 13 is retracted by driving the mold clamping motor 21, thereby separating the movable mold 33 from the fixed mold 32.

Further, the mold clamping device 10 of the present embodiment includes the mold clamping motor 21 as a drive source, but may have a hydraulic cylinder instead of the mold clamping motor 21. Further, the mold clamping device 10 has a linear motor for mold opening and closing, and may have an electromagnet for mold clamping.

The intermediate device 50 is disposed between the movable die 33 and the movable platen 13 . The intermediate device 50 has, for example, a block 51. The rear end portion of the compression member 36 is inserted in the internal space 52 of the block 51.

The ejector unit 60 ejects the molded article from the mold device 30 after the mold is opened. The ejector unit 60 has, for example, an ejector motor 61, a motion conversion mechanism 62, and an ejector rod 63.

The ejector motor 61 is attached to the rear of the movable platen 13. The ejector motor 61 has an encoder 61a. The encoder 61a detects the rotation angle of the output shaft of the ejector motor 61, and outputs a signal indicating the rotation angle to the control device 90.

The motion converting mechanism 62 converts the rotational motion of the ejector motor 61 into a linear motion of the ejector rod 63. The motion conversion mechanism 62 is constituted by, for example, a ball screw mechanism or the like.

The ejector rod 63 is retractable in the through hole of the movable platen 13. Eject The front end portion of the rod 63 is in contact with the rear end surface of the ejector plate 64.

The ejector plate 64 is retractable in the internal space 52 of the block 51. The front end face of the ejector plate 64 is in contact with the rear end portion of the compression member 36.

The ejector rod 63 is advanced by driving the ejector motor 61, whereby the compression member 36 advances. Then, the ejector lever 63 is retracted by driving the ejector motor 61, whereby the compression member 36 moves backward.

The ejector unit 60 functions as a driving device of the compression member 36. The compression member 36 is used in two aspects: (1) compression of the molding material in the mold device 30; and (2) ejection of the molded article from the mold device 30.

Next, the injection device 40 will be described. In the description of the injection device 40, unlike the description of the mold clamping device 10, the moving direction of the screw 43 at the time of filling (the left direction in the first drawing and the second drawing) is set to the front, and the screw 43 at the time of measurement is used. The movement direction (the right direction in the first drawing and the second drawing) is set to the rear.

The injection device 40 is disposed on the carriage Sb that is movable forward and backward with respect to the frame Fr, and is movable forward and backward with respect to the mold device 30. The injection device 40 is in contact with the mold device 30, and the molding material is filled into the mold device 30.

The injection device 40 includes, for example, a cylinder 41, a nozzle 42, a screw 43, a metering motor 45, an injection motor 46, and a pressure detector 47.

The cylinder 41 heats the molding material supplied from the supply port 41a to the inside. The supply port 41a is formed at the rear of the cylinder 41. A heating source such as a heater is provided on the outer circumference of the cylinder 41.

The nozzle 42 is provided at the front end portion of the cylinder 41 and is pressed against the mold device 30.

The screw 43 is disposed to be rotatable in the cylinder 41 and freely retractable.

The metering motor 45 rotates the screw 43, thereby feeding the molding material forward along the spiral groove of the screw 43. The molding material is gradually melted by the heat from the cylinder 41 while being sent forward. As the liquid molding material is sent to the front of the screw 43 and accumulated in the front portion of the cylinder 41, the screw 43 is retracted.

The injection motor 46 advances and retracts the screw 43. The injection motor 46 advances the screw 43 to discharge the liquid molding material accumulated in front of the screw 43 from the cylinder 41 and fill it into the mold device 30. Thereafter, the injection motor 46 pushes the screw 43 forward to apply pressure to the molding material in the cavity space 30. Can supplement insufficient forming materials. A motion conversion mechanism that converts the rotational motion of the injection motor 46 into a linear motion of the screw 43 is provided between the injection motor 46 and the screw 43.

The pressure detector 47 is disposed, for example, between the injection motor 46 and the screw 43, and detects the pressure from the molding material received by the screw 43 and the back pressure to the screw 43. The pressure from the molding material received by the screw 43 corresponds to the pressure acting on the molding material from the screw 43.

The operation of the injection device 40 is controlled by the control device 90. The control device 90 controls the filling process, the pressing process, the metering process, and the like.

In the filling process, the screw 43 is driven at a set speed by driving the injection motor 46, and the liquid molding material accumulated in front of the screw 43 is filled into the mold device 30. The position and speed of the screw 43 is detected, for example, by the encoder 46a of the injection motor 46. If the position of the screw 43 reaches the predetermined position, the filling process is switched to the holding process (so-called V/P cutting) change). The setting speed of the screw 43 can be changed in accordance with the position and time of the screw 43 and the like.

Further, in the filling process, after the position of the screw 43 reaches the predetermined position, the screw 43 can be temporarily stopped at the predetermined position, and then the V/P switching can be performed. Instead of the stop of the screw 43, it is also possible to perform the micro speed advancement or the reverse speed of the screw 43 before the V/P switching. When one of stopping, slightly advancing, and reversing is performed, the molding material mainly flows by the residual pressure or the like, so that the maximum pressure of the molding material can be reduced, and generation of burrs can be suppressed.

In the holding process, the screw 43 is pushed forward by driving the injection motor 46 at a set pressure, thereby applying pressure to the molding material in the mold device 30. Can supplement insufficient forming materials. The pressure of the forming material is detected, for example, by a pressure detector 47. During the holding process, the forming material in the mold unit 30 is gradually cooled, and at the end of the holding process, the inlet of the cavity space 34 is blocked by the solidified forming material. This state is referred to as a gate seal to prevent the forming material from flowing back from the cavity space 34. After the press process, the cooling process is started. In the cooling process, the solidification of the molding material in the cavity space 34 is performed. In order to shorten the forming cycle, the metering process can also be carried out in the cooling process.

In the metering process, the screw 43 is rotated at a set rotation speed by driving the metering motor 45, and the molding material is sent forward along the spiral groove of the screw 43. Accordingly, the forming material is gradually melted. The screw 43 is retracted as the liquid molding material is sent to the front of the screw 43 and accumulated in the front portion of the cylinder 41. The rotational speed of the screw 43 is, for example, by the encoder 45a of the metering motor 45. Detection.

In the metering process, in order to restrict the screw 43 from rapidly retreating, the set back pressure can be applied to the screw 43 by driving the injection motor 46. The back pressure applied to the screw 43 is detected by, for example, the pressure detector 47. When the screw 43 is retracted to a predetermined position and a predetermined amount of the molding material is accumulated in front of the screw 43, the measuring process is ended.

As shown in FIGS. 1 and 2, the control device 90 includes a CPU (Central Processing Unit) 91 and a memory medium 92 such as a memory. The control device 90 controls the mold clamping device 10, the injection device 40, the ejection device 60, and the like by causing the CPU 91 to execute a program stored in the memory medium 92.

Fig. 3 is a view showing a state in the mold device before the start of the compression operation of the injection molding machine according to the embodiment. The direction of the arrow in Fig. 3 indicates the flow direction of the molding material. Fig. 4 is a view showing a state in the mold device after completion of the compression operation of the injection molding machine according to the embodiment. The direction of the arrow in Fig. 4 indicates the compression direction of the compression member 36.

The control device 90 performs control of a compression operation (hereinafter simply referred to as "compression operation") of compressing the molding material M in the cavity space 34. The compression action is performed, for example, by advancing the compression member 36.

As shown in FIGS. 3 and 4, the start of the compression operation may be performed in the middle of the filling process, or may be performed before the flow front end of the molding material reaches the end of the flow path. Further, the end of the compression operation may be performed substantially simultaneously with the end of the filling process, or substantially simultaneously with the end of the flow of the molding material reaching the end of the flow path.

Further, the start timing of the compression operation is not particularly limited. For example, the beginning of the compression action can be performed after the start of the compression process. Similarly, the end time of the compression operation is not particularly limited. For example, the end of the compression action may be before the flow front end of the forming material reaches the end of the flow path, or it may be after the flow front end of the forming material reaches the end of the flow path.

A detector 37 that detects the flow of the molding material M in the mold device 30 is used to control the compression operation. Further, the number of the detectors 37 is one in the third and fourth figures, but it may be plural. A plurality of detectors 37 may be disposed at intervals along the flow path of the forming material M.

The detector 37 detects that the forming material M has reached a predetermined position. For example, the detector 37 detects that the flow front end of the forming material has reached a predetermined position. Alternatively, detector 37 can detect that a predetermined amount of formed material has reached a predetermined location (e.g., cavity space 34).

As the detector 37, for example, a temperature sensor or a pressure sensor is used. Both the temperature sensor and the pressure sensor can also be used as the detector 37.

When the molding material M reaches the installation position of the temperature sensor or its vicinity, since the temperature of the molding material M is higher than the temperature of the mold device 30, the measured value of the temperature sensor rises. It is possible to detect that the forming material M has reached a predetermined position based on the rise in the measured value of the temperature sensor. For example, when the measured value of the temperature sensor exceeds the set value, it is considered that the forming material M reaches the installation position of the temperature sensor or its vicinity. Alternatively, when the time differential value of the measured value of the temperature sensor exceeds the set value, it is considered that the forming material M reaches the installation position of the temperature sensor or its vicinity.

When the molding material M reaches the set position of the pressure sensor, since the pressure of the molding material M acts on the pressure sensor, the measured value of the pressure sensor rises. According to the rise of the measured value of the pressure sensor, it can be detected that the forming material M has reached a predetermined position. For example, when the measured value of the pressure sensor exceeds the set value, it is regarded as the set position at which the forming material M reaches the pressure sensor. Alternatively, when the time differential value of the measured value of the pressure sensor exceeds the set value, it is regarded as the set position at which the forming material M reaches the pressure sensor.

Further, as the detector 37, a pressure sensor 66 that detects the pressure acting on the member that performs the compression operation, a position sensor 65 that detects the position of the member that performs the compression operation, and the like can be used. This is because when the molding material M reaches the cavity space 34, the member that performs the compression operation is pressed. Examples of the member that performs the compression operation include a compression member 36, an ejector rod 63, and an ejector plate 64.

Further, in the present embodiment, the member that performs the compression operation also serves as the ejector member, but the member that performs the compression operation and the ejector member may be provided separately. At this time, as the detector 37, a pressure sensor that detects the pressure acting on the ejector member and a position sensor that detects the position of the ejector member can be used. This is because when the molding material M reaches the cavity space 34, the ejector member is pressed.

The control device 90 performs control of the compression operation in accordance with the detection result of the detector 37. The compression operation is adjusted in accordance with the filling condition of the molding material in the mold device 30, whereby fluctuations in processes other than the compression process (for example, the measurement process and the filling process) can be absorbed. Therefore, the quality of the molded article can be stabilized.

The control device 90 starts the compression operation, for example, based on the detection result of the detector 37. The timing at which the compression operation is started is adjusted according to the filling state of the molding material in the mold device 30, whereby fluctuations in the process other than the compression process can be absorbed.

For example, the start of the compression operation can be performed when the control device 90 detects that the molding material M has reached the predetermined position based on the detection result of the detector 37, and the elapsed time from the arrival reaches the preset compression operation start time. The fluctuation of the time at which the molding material M reaches a predetermined position can be absorbed, and the fluctuation of the highest pressure can be suppressed. The start time of the compression operation corresponds to the set time described in the patent application.

Further, the start of the compression operation may be performed when the control device 90 detects the flow end position of the molding material M based on the detection result of the detector 37 and the detection position reaches the preset compression operation start position. The detection of the flow front end position of the molding material M can also be performed by measuring, for example, the elapsed time from when the molding material M reaches a predetermined position. The longer the elapsed time, the closer the flow front end position of the forming material M is to the end point of the flow path.

Further, the start of the compression operation may be performed at a timing corresponding to a required time from the start of the filling process to the time when the molding material M reaches a predetermined position. For example, the longer the above-mentioned required time, the slower the flow of the molding material, so that the compression operation can be started at a slower time from the start of the filling process.

Further, the detector 37 is disposed on the upstream side of the inlet of the cavity space 34 in FIGS. 3 and 4, but may be disposed in the cavity space 34. The downstream side of the mouth. At this time, the above-described compression operation start time may be zero. Also, the detectors 37 can be disposed on both sides of the entrance of the cavity space 34.

The control device 90 may also perform position control of the compression operation after the compression operation is started. In the position control, the position of the member that performs the compression operation can be controlled. The control device 90 controls the position of the member that performs the compression operation to be the set position. The control may be any one of feedback control and feedforward control. Examples of the member that performs the compression operation include a compression member 36, an ejector rod 63, and an ejector plate 64.

The position of the member performing the compression action is detected by the position sensor 65. The position sensor 65 is attached to a member on the fixed side (for example, the block 51 of the intermediate device 50 in FIGS. 1 and 2), but may be attached to a movable member. Further, as the position sensor 65, the encoder 61a of the ejector motor 61 can be used.

The control device 90 can also perform position control of the compression operation in accordance with the detection result of the detector 37 after the compression operation is started. The set position of the member that performs the compression operation can be changed according to the filling state of the molding material M.

For example, the setting position of the member that performs the compression operation may be changed according to the elapsed time from the time when the molding material M detected by the detection result of the detector 37 reaches the predetermined position, or may be changed at a speed corresponding to the elapsed time.

Further, the set position of the member that performs the compression operation may be changed according to the flow end position of the molding material M detected based on the detection result of the detector 37, or may be changed at a speed corresponding to the flow end position.

Further, the setting position of the member that performs the compression operation can be changed at a speed corresponding to the required time required from the start of the filling process to the time when the molding material M reaches the predetermined position. For example, the longer the required time is, the slower the flow of the molding material M is. Therefore, the speed at which the set position of the member performing the compression operation is changed can be slow.

The control device 90 can perform pressure control of the compression action after the compression operation is started. In this pressure control, the pressure acting on the member that performs the compression operation can be controlled. The pressure of the member acting on the compression action corresponds to the pressure of the molding material M acting in the cavity space 34. Therefore, in the pressure control of the compression operation, the pressure acting on the member that performs the compression operation can be controlled by controlling the pressure of the molding material M acting in the cavity space 34. The control device 90 controls the pressure of the member acting on the compression operation to be the set pressure. The control may be any one of feedback control and feedforward control.

The pressure acting on the member performing the compression action is detected by the pressure sensor 66. The pressure sensor 66 is attached to the movable side member (for example, the compression member 36 in FIGS. 1 and 2), but may be attached to the fixed side member (for example, the fixed mold 32). Further, the pressure sensor 66 detects the pressure acting on the member that performs the compression operation by detecting the strain of the constituent members of the ejector unit 60 and the strain of the constituent members of the intermediate device 50.

The control device 90 can perform pressure control of the compression action in accordance with the detection result of the detector 37 after the compression operation is started. The pressure acting on the member that performs the compression operation can be changed according to the filling state of the molding material M, whereby Change the pressure acting on the forming material.

For example, the set pressure of the member that performs the compression operation may be changed according to the elapsed time from when the molding material M detected by the detection result of the detector 37 reaches the predetermined position, or may be changed at a speed corresponding to the elapsed time.

Further, the set pressure of the member that performs the compression operation may be changed according to the flow end position of the molding material M detected based on the detection result of the detector 37, or may be changed at a speed corresponding to the flow end position.

Further, the set pressure of the member that performs the compression operation can be changed at a speed corresponding to the required time required until the molding material M reaches the predetermined position from the start of the filling process. For example, the longer the required time is, the slower the flow of the molding material M is, and therefore the speed at which the set pressure of the member performing the compression operation is changed can be slow.

The control device can switch between position control and pressure control in the middle of the compression operation. Switching from position control to pressure control is possible, as well as switching from pressure control to position control.

For example, the control device 90 sequentially performs position control, pressure control, and position control in a process of performing a compression operation (hereinafter referred to as a "compression process").

The control device 90 performs position control at the beginning of the compression process to advance the compression member 36 to the set position, and the front surface of the compression member 36 can expand the molding material M. Further, when the compression process is started, the pressure of the molding material M in the cavity space 34 is unstable. The quality of the molded article is stabilized by the initial position control.

The control device 90 performs pressure control in the middle of the compression process to completely press the molding material M against the wall surface of the cavity space 34, thereby improving the transferability. Further, since the pressure of the molding material M is stabilized, the density of the molding material M is stabilized.

The control unit 90 performs position control at the end of the compression process to stabilize the final size and shape of the cavity space 34 to stabilize the size and shape of the molded article. Finally, by advancing the compression member 36, the cavity space 34 is filled with the molding material M, and the filling of the molding material M is finished. The press and cooling processes are performed after the filling process.

After the end of the compression process, in order to prevent the size of the cavity space 34 from changing during the pressurization process and the cooling process, position control can be continued. In this position control, the movement of the compression member 36 is prohibited. This position control can be performed until the start of the mold opening process.

Further, in the compression process of the present embodiment, position control, pressure control, and position control are sequentially performed, but the number of switching and the order are not particularly limited. For example, the number of times of switching may be one, or only position control and pressure control may be performed sequentially, or only pressure control and position control may be performed in sequence. Also, the number of times of switching can be three or more.

The control device 90 can switch the control of the compression action between the position control and the pressure control based on the detection result of the detector 37. The timing of switching can be changed in accordance with the filling condition of the molding material M.

For the switching of the control mode of the compression operation, for example, the control device 90 detects that the molding material M has reached the predetermined position based on the detection result of the detector 37, and the elapsed time from the arrival reaches the preset switching time. When the time is between.

Further, switching of the control method of the compression operation can be performed when the control device 90 detects the flow end position of the molding material M based on the detection result of the detector 37 and the detection position reaches a predetermined switching position.

After the control device 90 lowers the advancement speed of the screw 43 in the middle of the filling process, the control device 90 can control the compression operation based on the detection result of the detector 37. After the advancement speed of the screw 43 is lowered, the molding material mainly flows by the residual pressure or the like. Therefore, it is difficult to grasp the filling of the molding material in the mold device 30 in accordance with the position of the screw 43. Therefore, the effect of grasping the filling condition of the molding material in the mold device 30 can be remarkably obtained by the detector 37.

In the above, the embodiment of the injection molding machine has been described. However, the present invention is not limited to the above-described embodiments and the like, and various modifications and improvements can be made within the scope of the invention as described in the claims.

For example, the compression member 36 of the above embodiment is used in two aspects: (1) compression of the molding material in the mold device 30; (2) ejection of the molded article from the mold device 30, and may be used only for (1) compression. Not used for (2) ejection. At this time, the ejector member and the compression member 36 are disposed in the mold device 30, respectively.

When the ejector member and the compression member 36 are separately provided, the ejector unit 60 can function as a drive device that independently drives the ejector member and the compression member 36, or can function as a drive device that drives only the ejector member. In the latter case, a drive device that drives the compression member 36 is separately provided. For example, a hydraulic cylinder as the intermediate device 50 is used as A driving device that drives the compression member 36.

The compression member 36 of the above embodiment is disposed on the side of the movable mold 33, but may be disposed on the side of the fixed mold 32. At this time, the intermediate device 50 can be disposed between the fixed die 32 and the fixed platen 12. Further, the compression members 36 may be disposed on both sides of the movable mold 33 and the fixed mold 32, respectively.

In the above embodiment, the ejector unit 60 is used for the compression operation of the molding material in the cavity space, but the mold clamping device 10 may be used. In the latter case, the intermediate device 50 may not be provided, and the mold device 30A shown in Fig. 5 may be used instead of the mold device 30.

The mold device 30A has a fixed mold 32A and a movable mold 33A. The fixed mold 32A is attached to the fixed platen 12, and the movable mold 33A is attached to the movable platen 13 without passing through the intermediate device 50 shown in Fig. 1 or the like.

As shown in Fig. 5, the movable mold 33A has a mold main body portion 33Aa, a frame portion 33Ab, and a spring portion 33Ac. The mold main body portion 33Aa is attached to the movable platen 13. The frame portion 33Ab surrounds the convex portion of the mold main body portion 33Aa, and is coupled to the mold main body portion 33Aa via the spring portion 33Ac.

The mold clamping device 10 presses the frame portion 33Ab against the fixed mold 32A by advancing the movable platen 13, thereby contracting the spring portion 33Ac. The mold main body portion 33Aa is advanced to a predetermined position, and a cavity space 34A is formed between the mold main body portion 33Aa and the fixed mold 32A. Next, the mold clamping device 10 can further compress the molding material in the cavity space 34A by advancing the movable platen 13 further.

In addition, in the fifth figure, the movable mold 33A includes the mold main body portion 33Aa, the frame portion 33Ab, and the spring portion 33Ac, but it may be substituted for the movable mold. The fixed mold 32A is provided with these members by 33A. In addition, in the fifth drawing, a spring is used as a connecting portion that connects the mold main body portion 33Aa and the frame portion 33Ab, but a cylinder or the like may be used. Further, one of the movable mold 33A and the fixed mold 32A may be provided with a convex portion, and the other of the movable mold 33A and the fixed mold 32A may be provided with a concave portion, and the convex portion may be inserted into the concave portion, whereby the convex portion may be provided. A cavity space is formed between the top surface and the bottom surface of the recess.

The injection device 40 of the above embodiment is a coaxial screw system, but may be a pre-molding method. In the injection molding apparatus of the pre-molding method, the molding material melted in the plasticating cylinder is supplied to the shooting cylinder, and the molding material is ejected from the shooting cylinder into the mold device. The screw is disposed in the plasticizing cylinder so as to be freely rotatable or rotatable, and the plunger is retractably disposed in the shooting cylinder.

30‧‧‧Molding device

32‧‧‧Fixed mode

33‧‧‧ movable mold

36‧‧‧Compressed components

37‧‧‧Detector

M‧‧‧ molding materials

Claims (8)

An injection molding machine comprising: a detector for detecting a flow of a molding material in a mold device; and a control device for controlling a compression action of compressing the molding material in a cavity space in the mold device according to a detection result of the detector . The injection molding machine according to claim 1, wherein the control device starts the compression operation based on a detection result of the detector. The injection molding machine according to claim 1 or 2, wherein the control device detects that the molding material has reached a predetermined position based on a detection result of the detector. The injection molding machine according to claim 1 or 2, wherein the control device detects that the flow front end of the molding material has reached a predetermined position based on a detection result of the detector. The injection molding machine according to the third aspect of the invention, wherein the control device starts the compression operation when detecting that the elapsed time from the arrival of the arrival reaches a set time. The injection molding machine according to claim 1 or 2, wherein the control device performs the position according to the detection result of the detector. Control, the position control is a position to control a member that performs the aforementioned compression action. The injection molding machine according to the first or second aspect of the invention, wherein the control device performs pressure control in accordance with a detection result of the detector, wherein the pressure control controls a pressure acting on a member that performs the compression operation. The injection molding machine according to the first or second aspect of the invention, wherein the control device performs switching between a position control of the compression operation and a pressure control of the compression operation in accordance with a detection result of the detector.