WO2022210778A1

WO2022210778A1 - Injection molding machine

Info

Publication number: WO2022210778A1
Application number: PCT/JP2022/015678
Authority: WO
Inventors: 弘康谷藤; 大吾堀田; 大大野
Original assignee: 住友重機械工業株式会社
Priority date: 2021-03-31
Filing date: 2022-03-29
Publication date: 2022-10-06
Also published as: JPWO2022210778A1; CN116745046A; DE112022001947T5

Abstract

An injection molding machine according to the present invention comprises an injection device that fills a molding material into a die device, and a control device that controls the injection device. The injection device comprises a cylinder that heats the molding material, a screw disposed inside of the cylinder, and a metering motor that rotates the screw. The control device has a correction control unit which, on the basis of the circumferential directional position of the screw which varies on the basis of the operation of the metering motor, corrects a pressure setting value used in pressure control of the screw, or corrects a detection value output from a pressure detector that detects the pressure acting on the screw.

Description

Injection molding machine

The present invention relates to an injection molding machine.

An injection molding machine is equipped with a cylinder to which resin pellets are supplied as a molding material, and a heater that heats the cylinder to melt the resin pellets. An injection molding machine manufactures a molded product by melting resin pellets in a cylinder and filling a cavity space in a mold device with the melted resin.

Various sensors are installed in the injection molding machine. And it is preferred to recognize the exact torque and stress from the values detected by the sensors.

JP 2009-045904 A

Patent Document 1 measures and stores the rotational torque during weighing, and inputs it into a function assumed in advance to set the allowable upper limit of the rotational torque of the screw, so complicated material mechanical strength calculations are not required. Even without it, torque monitoring based on the allowable upper limit is realized.

On the other hand, in order to properly control and monitor injection molding machines, it is desired to detect not only rotational torque but also accurate resin pressure. However, unbalanced loads due to friction of drive parts and changes in attitude affect the detected values of load detectors.

One aspect of the present invention provides a technique for improving the accuracy of pressure control for filling the molding material and detection of the pressure acting on the screw.

An injection molding machine according to one aspect of the present invention has an injection device that fills a mold device with molding material, and a control device that controls the injection device. The injection device has a cylinder that heats the molding material, a screw that is arranged in the cylinder, and a metering motor that rotates the screw. The control device corrects the pressure set value used for the screw pressure control based on the circumferential position of the screw, which changes based on the operation of the metering motor, or a pressure detector that detects the pressure acting on the screw. It has a correction control section for correcting the detection value output from.

An injection molding machine according to one aspect of the present invention has an injection device that fills a mold device with molding material, and a control device that controls the injection device. The injection device has a cylinder that heats the molding material, a screw that is arranged in the cylinder, and an injection motor that moves the screw along the cylinder. The control device corrects the pressure set value used for the screw pressure control based on the axial position of the screw, which changes based on the operation of the injection motor, or a pressure detector that detects the pressure acting on the screw. It has a correction control section for correcting the detection value output from.

An injection molding machine according to one aspect of the present invention has an injection device that fills a mold device with molding material, and a control device that controls the injection device. The injection device has a cylinder that heats the molding material, a screw arranged in the cylinder, and an injection motor that moves the screw. The controller corrects the pressure setpoint used to control the screw pressure based on the speed of the screw, which varies based on the operation of the injection motor, or the pressure output from the pressure detector that detects the pressure acting on the screw. and a correction control section for correcting the detected value.

According to one aspect of the present invention, the influence of disturbance is suppressed, and the precision of the pressure control for filling the molding material and the detection of the pressure acting on the screw is improved.

FIG. 1 is a diagram showing a state of an injection molding machine according to one embodiment when mold opening is completed. FIG. 2 is a diagram showing a state of the injection molding machine according to the embodiment at the time of mold clamping. FIG. 3 is a diagram showing a state at the start of injection of the injection device according to one embodiment. FIG. 4 is a diagram showing a state of the injection device according to one embodiment when injection is completed. FIG. 5 is a partially enlarged view of the injection completion state of the injection device according to one embodiment. FIG. 6 is a diagram showing functional blocks of components of a control device according to an embodiment. FIG. 7 is a conceptual diagram showing the pressure detected by the load detector during weighing according to the first embodiment. FIG. 8 is a diagram illustrating the relationship between the value detected by the load detector and the force due to the resin pressure according to the first embodiment. FIG. 9 is a diagram showing detection values detected by the load detector when the injection spline shaft is moved while the position of the screw in the circumferential direction is fixed according to the first embodiment. 10 is a diagram exemplifying a table in a correction information storage unit registered in a registration unit according to the first embodiment; FIG. FIG. 11 is a diagram showing a flowchart for registering correction values in a correction information storage unit in the control device according to the first embodiment. FIG. 12 is a flowchart for performing display processing during weighing in the control device according to the first embodiment. FIG. 13 is a diagram illustrating resistance (including friction) that changes according to the circumferential position (rotational angle) of the screw or the position of the screw (phase of injection spline shaft). FIG. 14 is a diagram showing the structure of a speed correction value storage table held by a correction information storage unit according to the second embodiment. FIG. 15 is a diagram exemplifying variations in correction values calculated by the correction control unit according to the second embodiment using equation (3).

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each drawing, the same or corresponding configurations are denoted by the same or corresponding reference numerals, and description thereof may be omitted.

FIG. 1 is a diagram showing a state of the injection molding machine according to one embodiment when mold opening is completed. FIG. 2 is a diagram showing a state of the injection molding machine according to the embodiment at the time of mold clamping. In this specification, the X-axis direction, Y-axis direction and Z-axis direction are directions perpendicular to each other. The X-axis direction and Y-axis direction represent the horizontal direction, and the Z-axis direction represents the vertical direction. When the mold clamping device 100 is of a horizontal type, the X-axis direction is the mold opening/closing direction, and the Y-axis direction is the width direction of the injection molding machine 10 . The Y-axis direction negative side is called the operating side, and the Y-axis direction positive side is called the non-operating side.

As shown in FIGS. 1 and 2, the injection molding machine 10 includes a mold clamping device 100 that opens and closes a mold device 800, an ejector device 200 that ejects a molded product molded by the mold device 800, and the mold device 800. a moving device 400 for moving the injection device 300 forward and backward with respect to the mold device 800; a control device 700 for controlling each component of the injection molding machine 10; and a frame 900 that supports the components. The frame 900 includes a mold clamping device frame 910 that supports the mold clamping device 100 and an injection device frame 920 that supports the injection device 300 . The mold clamping device frame 910 and the injection device frame 920 are each installed on the floor 2 via leveling adjusters 930 . A control device 700 is arranged in the inner space of the injection device frame 920 . Each component of the injection molding machine 10 will be described below.

(mold clamping device)
In the description of the mold clamping device 100, the moving direction of the movable platen 120 when the mold is closed (for example, the X-axis positive direction) is defined as the front, and the moving direction of the movable platen 120 when the mold is opened is defined as the rear (for example, the X-axis negative direction). do.

The mold clamping device 100 performs mold closing, pressure increase, mold clamping, depressurization, and mold opening of the mold device 800 . Mold apparatus 800 includes a fixed mold 810 and a movable mold 820 .

The mold clamping device 100 is, for example, a horizontal type, and the mold opening/closing direction is horizontal. The mold clamping device 100 includes a stationary platen 110 to which a stationary mold 810 is attached, a movable platen 120 to which a movable mold 820 is attached, a moving mechanism 102 that moves the movable platen 120 in the mold opening/closing direction with respect to the stationary platen 110, have

The fixed platen 110 is fixed to the mold clamping device frame 910 . A stationary mold 810 is attached to the surface of the stationary platen 110 facing the movable platen 120 .

The movable platen 120 is arranged movably in the mold opening/closing direction with respect to the mold clamping device frame 910 . A guide 101 for guiding the movable platen 120 is laid on the mold clamping device frame 910 . A movable die 820 is attached to the surface of the movable platen 120 facing the fixed platen 110 .

The moving mechanism 102 moves the movable platen 120 back and forth with respect to the fixed platen 110 to perform mold closing, pressure increase, mold clamping, pressure release, and mold opening of the mold device 800 . The moving mechanism 102 includes a toggle support 130 spaced apart from the stationary platen 110 , tie bars 140 connecting the stationary platen 110 and the toggle support 130 , and moving the movable platen 120 relative to the toggle support 130 in the mold opening/closing direction. a toggle mechanism 150 that operates the toggle mechanism 150, a mold clamping motor 160 that operates the toggle mechanism 150, a motion conversion mechanism 170 that converts the rotary motion of the mold clamping motor 160 into a linear motion, and a mold that adjusts the interval between the stationary platen 110 and the toggle support 130. and a thickness adjustment mechanism 180 .

The toggle support 130 is spaced apart from the fixed platen 110 and mounted on the mold clamping device frame 910 so as to be movable in the mold opening/closing direction. In addition, the toggle support 130 may be arranged so as to be movable along a guide laid on the mold clamping device frame 910 . The guides of the toggle support 130 may be common with the guides 101 of the movable platen 120 .

In this embodiment, the fixed platen 110 is fixed to the mold clamping device frame 910, and the toggle support 130 is arranged to be movable in the mold opening/closing direction with respect to the mold clamping device frame 910. Fixed to the device frame 910 , the stationary platen 110 may be arranged to be movable relative to the mold clamping device frame 910 in the mold opening/closing direction.

The tie bar 140 connects the stationary platen 110 and the toggle support 130 with a gap L in the mold opening/closing direction. A plurality of (for example, four) tie bars 140 may be used. The multiple tie bars 140 are arranged parallel to the mold opening/closing direction and extend according to the mold clamping force. At least one tie bar 140 may be provided with a tie bar strain detector 141 that detects strain of the tie bar 140 . Tie-bar distortion detector 141 sends a signal indicating the detection result to control device 700 . The detection result of the tie bar strain detector 141 is used for detection of mold clamping force and the like.

In this embodiment, the tie bar strain detector 141 is used as a mold clamping force detector that detects the mold clamping force, but the present invention is not limited to this. The mold clamping force detector is not limited to the strain gauge type, but may be of piezoelectric type, capacitive type, hydraulic type, electromagnetic type, etc., and its mounting position is not limited to the tie bar 140 either.

The toggle mechanism 150 is arranged between the movable platen 120 and the toggle support 130 and moves the movable platen 120 relative to the toggle support 130 in the mold opening/closing direction. The toggle mechanism 150 has a crosshead 151 that moves in the mold opening/closing direction, and a pair of link groups that bend and stretch as the crosshead 151 moves. A pair of link groups each has a first link 152 and a second link 153 that are connected by a pin or the like so as to be bendable and stretchable. The first link 152 is swingably attached to the movable platen 120 with a pin or the like. The second link 153 is swingably attached to the toggle support 130 with a pin or the like. A second link 153 is attached to the crosshead 151 via a third link 154 . When the crosshead 151 advances and retreats with respect to the toggle support 130 , the first link 152 and the second link 153 bend and stretch, and the movable platen 120 advances and retreats with respect to the toggle support 130 .

The configuration of the toggle mechanism 150 is not limited to the configurations shown in FIGS. 1 and 2. For example, in FIGS. 1 and 2, the number of nodes in each link group is five, but the number may be four, and one end of the third link 154 is coupled to the node between the first link 152 and the second link 153. may be

The mold clamping motor 160 is attached to the toggle support 130 and operates the toggle mechanism 150 . The mold clamping motor 160 advances and retreats the crosshead 151 with respect to the toggle support 130 , thereby bending and stretching the first link 152 and the second link 153 to advance and retreat the movable platen 120 with respect to the toggle support 130 . The mold clamping motor 160 is directly connected to the motion conversion mechanism 170, but may be connected to the motion conversion mechanism 170 via a belt, pulley, or the like.

The motion conversion mechanism 170 converts rotary motion of the mold clamping motor 160 into linear motion of the crosshead 151 . The motion conversion mechanism 170 includes a threaded shaft and a threaded nut that screws onto the threaded shaft. Balls or rollers may be interposed between the screw shaft and the screw nut.

Under the control of the control device 700, the mold clamping device 100 performs a mold closing process, a pressure increasing process, a mold clamping process, a depressurizing process, a mold opening process, and the like.

In the mold closing process, the mold clamping motor 160 is driven to advance the crosshead 151 to the mold closing completion position at the set movement speed, thereby advancing the movable platen 120 and bringing the movable mold 820 into contact with the fixed mold 810. . The position and moving speed of the crosshead 151 are detected using, for example, a mold clamping motor encoder 161 or the like. The mold clamping motor encoder 161 detects rotation of the mold clamping motor 160 and sends a signal indicating the detection result to the control device 700 .

The crosshead position detector for detecting the position of the crosshead 151 and the crosshead movement speed detector for detecting the movement speed of the crosshead 151 are not limited to the mold clamping motor encoder 161, and general ones are used. can. Further, the movable platen position detector for detecting the position of the movable platen 120 and the movable platen moving speed detector for detecting the moving speed of the movable platen 120 are not limited to the mold clamping motor encoder 161, and general ones are used. can.

In the pressurization step, the mold clamping motor 160 is further driven to further advance the crosshead 151 from the mold closing completion position to the mold clamping position, thereby generating mold clamping force.

In the mold clamping process, the mold clamping motor 160 is driven to maintain the position of the crosshead 151 at the mold clamping position. In the mold clamping process, the mold clamping force generated in the pressurizing process is maintained. In the mold clamping process, a cavity space 801 (see FIG. 2) is formed between the movable mold 820 and the fixed mold 810, and the injection device 300 fills the cavity space 801 with a liquid molding material. A molded product is obtained by solidifying the filled molding material.

The number of cavity spaces 801 may be one or plural. In the latter case, multiple moldings are obtained simultaneously. The insert material may be arranged in part of the cavity space 801 and the other part of the cavity space 801 may be filled with the molding material. A molded product in which the insert material and the molding material are integrated is obtained.

In the depressurization process, the mold clamping motor 160 is driven to retract the crosshead 151 from the mold clamping position to the mold opening start position, thereby retracting the movable platen 120 and reducing the mold clamping force. The mold opening start position and the mold closing completion position may be the same position.

In the mold opening step, the mold clamping motor 160 is driven to retract the crosshead 151 from the mold opening start position to the mold opening completion position at a set moving speed, thereby retracting the movable platen 120 and moving the movable mold 820 to the fixed metal. away from the mold 810; After that, the ejector device 200 ejects the molded product from the movable mold 820 .

The setting conditions in the mold closing process, pressure rising process, and mold clamping process are collectively set as a series of setting conditions. For example, the moving speed and position of the crosshead 151 (including the mold closing start position, the moving speed switching position, the mold closing completion position, and the mold clamping position) and the mold clamping force in the mold closing process and the pressurizing process are set as a series of setting conditions. are collectively set as The mold closing start position, the movement speed switching position, the mold closing completion position, and the mold clamping position are arranged in this order from the rear side to the front side, and represent the start point and end point of the section in which the movement speed is set. A moving speed is set for each section. The moving speed switching position may be one or plural. The moving speed switching position does not have to be set. Only one of the mold clamping position and the mold clamping force may be set.

The setting conditions in the depressurization process and the mold opening process are set in the same way. For example, the moving speed and position of the crosshead 151 (mold opening start position, moving speed switching position, and mold opening completion position) in the depressurizing process and the mold opening process are collectively set as a series of setting conditions. The mold opening start position, the movement speed switching position, and the mold opening completion position are arranged in this order from the front side to the rear side, and represent the start point and end point of the section for which the movement speed is set. A moving speed is set for each section. The moving speed switching position may be one or plural. The moving speed switching position does not have to be set. The mold opening start position and the mold closing completion position may be the same position. Also, the mold opening completion position and the mold closing start position may be the same position.

Note that instead of the moving speed, position, etc. of the crosshead 151, the moving speed, position, etc. of the movable platen 120 may be set. Also, the mold clamping force may be set instead of the position of the crosshead (for example, mold clamping position) or the position of the movable platen.

By the way, the toggle mechanism 150 amplifies the driving force of the mold clamping motor 160 and transmits it to the movable platen 120 . The amplification factor is also called toggle factor. The toggle magnification changes according to the angle θ formed between the first link 152 and the second link 153 (hereinafter also referred to as “link angle θ”). The link angle θ is obtained from the position of the crosshead 151 . When the link angle θ is 180°, the toggle magnification becomes maximum.

When the thickness of the mold device 800 changes due to replacement of the mold device 800 or temperature change of the mold device 800, the mold thickness is adjusted so that a predetermined mold clamping force can be obtained during mold clamping. In the mold thickness adjustment, for example, the distance L between the fixed platen 110 and the toggle support 130 is adjusted so that the link angle θ of the toggle mechanism 150 becomes a predetermined angle when the movable mold 820 touches the fixed mold 810 . to adjust.

The mold clamping device 100 has a mold thickness adjusting mechanism 180. The mold thickness adjustment mechanism 180 adjusts the mold thickness by adjusting the distance L between the stationary platen 110 and the toggle support 130 . The timing of mold thickness adjustment is, for example, between the end of a molding cycle and the start of the next molding cycle. The mold thickness adjusting mechanism 180 is, for example, a threaded shaft 181 formed at the rear end of the tie bar 140, a screw nut 182 held by the toggle support 130 so as to be rotatable and non-retractable, and screwed to the threaded shaft 181. and a mold thickness adjusting motor 183 that rotates the screw nut 182 .

A threaded shaft 181 and a threaded nut 182 are provided for each tie bar 140 . The rotational driving force of the mold thickness adjusting motor 183 may be transmitted to the multiple screw nuts 182 via the rotational driving force transmission portion 185 . Multiple screw nuts 182 can be rotated synchronously. By changing the transmission path of the rotational driving force transmission portion 185, it is also possible to rotate the plurality of screw nuts 182 individually.

The rotational driving force transmission section 185 is configured by, for example, gears. In this case, a driven gear is formed on the outer circumference of each screw nut 182, a driving gear is attached to the output shaft of the mold thickness adjusting motor 183, and an intermediate gear that meshes with a plurality of driven gears and the driving gear is formed in the central portion of the toggle support 130. rotatably held. Note that the rotational driving force transmission section 185 may be configured by a belt, a pulley, or the like instead of the gear.

The operation of the mold thickness adjusting mechanism 180 is controlled by the control device 700. The control device 700 drives the mold thickness adjusting motor 183 to rotate the screw nut 182 . As a result, the position of toggle support 130 with respect to tie bar 140 is adjusted, and the distance L between stationary platen 110 and toggle support 130 is adjusted. A plurality of mold thickness adjusting mechanisms may be used in combination.

The interval L is detected using the mold thickness adjustment motor encoder 184. The mold thickness adjusting motor encoder 184 detects the amount and direction of rotation of the mold thickness adjusting motor 183 and sends a signal indicating the detection result to the control device 700 . The detection result of the mold thickness adjustment motor encoder 184 is used for monitoring and controlling the position and interval L of the toggle support 130 . The toggle support position detector that detects the position of the toggle support 130 and the gap detector that detects the gap L are not limited to the mold thickness adjustment motor encoder 184, and general ones can be used.

The mold clamping device 100 may have a mold temperature controller that adjusts the temperature of the mold device 800 . The mold device 800 has a flow path for a temperature control medium inside. The mold temperature controller adjusts the temperature of the mold device 800 by adjusting the temperature of the temperature control medium supplied to the flow path of the mold device 800 .

Although the mold clamping device 100 of this embodiment is a horizontal type in which the mold opening/closing direction is horizontal, it may be a vertical type in which the mold opening/closing direction is a vertical direction.

Although the mold clamping device 100 of this embodiment has the mold clamping motor 160 as a drive source, the mold clamping motor 160 may be replaced by a hydraulic cylinder. Further, the mold clamping device 100 may have a linear motor for mold opening and closing and an electromagnet for mold clamping.

(ejector device)
In the description of the ejector device 200, as in the description of the mold clamping device 100, the moving direction of the movable platen 120 when the mold is closed (for example, the positive direction of the X axis) is defined as the front, and the moving direction of the movable platen 120 when the mold is opened (for example, X-axis negative direction) will be described as the rear.

The ejector device 200 is attached to the movable platen 120 and advances and retreats together with the movable platen 120 . The ejector device 200 has an ejector rod 210 that ejects a molded product from the mold device 800 and a drive mechanism 220 that moves the ejector rod 210 in the moving direction of the movable platen 120 (X-axis direction).

The ejector rod 210 is disposed in a through hole of the movable platen 120 so that it can move back and forth. The front end of ejector rod 210 contacts ejector plate 826 of movable mold 820 . The front end of ejector rod 210 may or may not be connected to ejector plate 826 .

The drive mechanism 220 has, for example, an ejector motor and a motion conversion mechanism that converts the rotary motion of the ejector motor into the linear motion of the ejector rod 210 . The motion conversion mechanism includes a threaded shaft and a threaded nut that screws onto the threaded shaft. Balls or rollers may be interposed between the screw shaft and the screw nut.

The ejector device 200 performs an ejecting process under the control of the control device 700 . In the ejecting step, the ejector plate 826 is moved forward by advancing the ejector rod 210 from the standby position to the ejecting position at a set moving speed to eject the molded product. After that, the ejector motor is driven to retract the ejector rod 210 at the set movement speed, and the ejector plate 826 is retracted to the original standby position.

The position and moving speed of the ejector rod 210 are detected using, for example, an ejector motor encoder. The ejector motor encoder detects rotation of the ejector motor and sends a signal indicating the detection result to the control device 700 . The ejector rod position detector for detecting the position of the ejector rod 210 and the ejector rod moving speed detector for detecting the moving speed of the ejector rod 210 are not limited to ejector motor encoders, and general ones can be used.

(Injection device)
In the description of the injection device 300, unlike the description of the mold clamping device 100 and the description of the ejector device 200, the axial direction of the screw 330 during filling (for example, the negative direction of the X axis among the directions in which the screw 330 can move) is The description will be made with the forward direction and the axial direction of the screw 330 during weighing (for example, the positive direction of the X-axis among the directions in which the screw 330 can move) as the rearward direction.

The injection device 300 is installed on a slide base 301 , and the slide base 301 is arranged to move forward and backward relative to the injection device frame 920 . The injection device 300 is arranged to move back and forth with respect to the mold device 800 . The injection device 300 touches the mold device 800 and fills the cavity space 801 in the mold device 800 with the molding material. The injection device 300 includes, for example, a cylinder 310 that heats the molding material, a nozzle 320 that is provided at the front end of the cylinder 310, a screw 330 that is rotatably arranged in the cylinder 310 so that it can move back and forth, and a screw that rotates. , an injection motor 350 for advancing and retreating the screw 330 , and a load detector 360 for detecting the load transmitted between the injection motor 350 and the screw 330 .

The cylinder 310 heats the molding material supplied inside from the supply port 311 . The molding material includes, for example, resin. The molding material is formed into, for example, a pellet shape and supplied to the supply port 311 in a solid state. A supply port 311 is formed in the rear portion of the cylinder 310 . A cooler 312 such as a water-cooled cylinder is provided on the outer circumference of the rear portion of the cylinder 310 . A heater 313 such as a band heater and a temperature detector 314 are provided on the outer periphery of the cylinder 310 ahead of the cooler 312 .

The cylinder 310 is divided into a plurality of zones in the axial direction of the cylinder 310 (for example, the X-axis direction). A heater 313 and a temperature detector 314 are provided in each of the plurality of zones. A set temperature is set for each of the plurality of zones, and the controller 700 controls the heater 313 so that the temperature detected by the temperature detector 314 becomes the set temperature.

The nozzle 320 is provided at the front end of the cylinder 310 and pressed against the mold device 800 . A heater 313 and a temperature detector 314 are provided around the nozzle 320 . The controller 700 controls the heater 313 so that the detected temperature of the nozzle 320 becomes the set temperature.

The screw 330 is arranged in the cylinder 310 so as to be rotatable and advanceable. When the screw 330 is rotated, the molding material is sent forward along the helical groove of the screw 330 . The molding material is gradually melted by the heat from the cylinder 310 while being fed forward. The screw 330 is retracted as liquid molding material is fed forward of the screw 330 and accumulated at the front of the cylinder 310 . After that, when the screw 330 is advanced, the liquid molding material accumulated in front of the screw 330 is injected from the nozzle 320 and filled in the mold device 800 .

A backflow prevention ring 331 is movably attached to the front of the screw 330 as a backflow prevention valve that prevents backflow of the molding material from the front to the rear of the screw 330 when the screw 330 is pushed forward.

The anti-backflow ring 331 is pushed backward by the pressure of the molding material in front of the screw 330 when the screw 330 is advanced, and is relatively to the screw 330 until it reaches a closed position (see FIG. 2) that blocks the flow path of the molding material. fall back. This prevents the molding material accumulated in front of the screw 330 from flowing backward.

On the other hand, the anti-backflow ring 331 is pushed forward by the pressure of the molding material sent forward along the helical groove of the screw 330 when the screw 330 is rotated, and is in an open position where the flow path of the molding material is opened. (see FIG. 1) relative to the screw 330. Thereby, the molding material is sent forward of the screw 330 .

The anti-backflow ring 331 may be either a co-rotating type that rotates together with the screw 330 or a non-co-rotating type that does not rotate together with the screw 330 .

It should be noted that the injection device 300 may have a drive source that advances and retracts the backflow prevention ring 331 with respect to the screw 330 between the open position and the closed position.

The metering motor 340 rotates the screw 330 . The drive source for rotating the screw 330 is not limited to the metering motor 340, and may be, for example, a hydraulic pump.

The injection motor 350 moves the screw 330 forward and backward. Between the injection motor 350 and the screw 330, a motion conversion mechanism or the like that converts the rotary motion of the injection motor 350 into the linear motion of the screw 330 is provided. The motion conversion mechanism has, for example, a screw shaft and a screw nut screwed onto the screw shaft. Balls, rollers, or the like may be provided between the screw shaft and the screw nut. The drive source for advancing and retreating the screw 330 is not limited to the injection motor 350, and may be, for example, a hydraulic cylinder.

A load detector 360 detects the load transmitted between the injection motor 350 and the screw 330 . The detected load is converted into pressure by the control device 700 . The load detector 360 is provided in a load transmission path between the injection motor 350 and the screw 330 and detects the load acting on the load detector 360 .

The load detector 360 sends a detected load signal to the control device 700 . The load detected by the load detector 360 is converted into the pressure acting between the screw 330 and the molding material, the pressure received by the screw 330 from the molding material, the back pressure on the screw 330, and the pressure acting on the molding material from the screw 330. Used for control and monitoring of pressure, etc.

Note that the pressure detector that detects the pressure of the molding material is not limited to the load detector 360, and a general one can be used. For example, a nozzle pressure sensor or a mold internal pressure sensor may be used. A nozzle pressure sensor is installed at the nozzle 320 . The mold internal pressure sensor is installed inside the mold apparatus 800 .

Under the control of the control device 700, the injection device 300 performs a weighing process, a filling process, a holding pressure process, and the like. The filling process and the holding pressure process may collectively be called an injection process.

In the weighing process, the weighing motor 340 is driven to rotate the screw 330 at a set rotation speed, and the molding material is fed forward along the helical groove of the screw 330. Along with this, the molding material is gradually melted. The screw 330 is retracted as liquid molding material is fed forward of the screw 330 and accumulated at the front of the cylinder 310 . The rotation speed of the screw 330 is detected using a metering motor encoder 341, for example. Weighing motor encoder 341 detects the rotation of weighing motor 340 and sends a signal indicating the detection result to control device 700 . Note that the screw rotation speed detector for detecting the rotation speed of the screw 330 is not limited to the weighing motor encoder 341, and a general one can be used.

In the metering process, the injection motor 350 may be driven to apply a set back pressure to the screw 330 in order to limit rapid retraction of the screw 330 . The back pressure on the screw 330 is detected using a load detector 360, for example. The metering process is completed when the screw 330 is retracted to the metering completion position and a predetermined amount of molding material is accumulated in front of the screw 330 .

The axial position and rotational speed of the screw 330 in the weighing process are collectively set as a series of setting conditions. For example, a weighing start position, rotation speed switching position, and weighing completion position are set. These positions are arranged in this order from the front side to the rear side, and represent the start point and end point of the section in which the rotational speed is set. A rotation speed is set for each section. The rotational speed switching position may be one or plural. The rotation speed switching position does not have to be set. Also, the back pressure is set for each section.

In the filling process, the injection motor 350 is driven to advance the screw 330 at a set movement speed, and the liquid molding material accumulated in front of the screw 330 is filled into the cavity space 801 in the mold device 800 . The position and moving speed of the screw 330 are detected using an injection motor encoder 351, for example. The injection motor encoder 351 detects rotation of the injection motor 350 and sends a signal indicating the detection result to the control device 700 . When the position of the screw 330 reaches the set position, switching from the filling process to the holding pressure process (so-called V/P switching) is performed. The position at which V/P switching takes place is also called the V/P switching position. The set moving speed of the screw 330 may be changed according to the position of the screw 330, time, and the like.

The position and movement speed of the screw 330 in the filling process are collectively set as a series of setting conditions. For example, a filling start position (also called an “injection start position”), a moving speed switching position, and a V/P switching position are set. These positions are arranged in this order from the rear side to the front side, and represent the start point and end point of the section for which the movement speed is set. A moving speed is set for each section. The moving speed switching position may be one or plural. The moving speed switching position does not have to be set.

The upper limit value of the pressure of the screw 330 is set for each section in which the moving speed of the screw 330 is set. The pressure of screw 330 is detected by load detector 360 . When the pressure of the screw 330 is below the set pressure, the screw 330 is advanced at the set travel speed. On the other hand, when the pressure of the screw 330 exceeds the set pressure, the screw 330 is advanced at a moving speed slower than the set moving speed so that the pressure of the screw 330 is equal to or less than the set pressure for the purpose of mold protection.

It should be noted that after the position of the screw 330 reaches the V/P switching position in the filling process, the screw 330 may be temporarily stopped at the V/P switching position, and then the V/P switching may be performed. Immediately before the V/P switching, instead of stopping the screw 330, the screw 330 may be slowly advanced or slowly retracted. Further, the screw position detector for detecting the position of the screw 330 and the screw moving speed detector for detecting the moving speed of the screw 330 are not limited to the injection motor encoder 351, and general ones can be used.

In the holding pressure process, the injection motor 350 is driven to push the screw 330 forward, and the pressure of the molding material at the front end of the screw 330 (hereinafter also referred to as “holding pressure”) is maintained at the set pressure. The remaining molding material is pushed toward the mold device 800 . A shortage of molding material due to cooling shrinkage in the mold apparatus 800 can be replenished. The holding pressure is detected using the load detector 360, for example. The set value of the holding pressure may be changed according to the elapsed time from the start of the holding pressure process. A plurality of holding pressures and holding times for holding the holding pressure in the holding pressure step may be set respectively, and may be collectively set as a series of setting conditions.

In the holding pressure process, the molding material in the cavity space 801 inside the mold device 800 is gradually cooled, and when the holding pressure process is completed, the entrance of the cavity space 801 is closed with the solidified molding material. This state is called a gate seal, and prevents the molding material from flowing back from the cavity space 801 . After the holding pressure process, the cooling process is started. In the cooling process, the molding material inside the cavity space 801 is solidified. A metering step may be performed during the cooling step for the purpose of shortening the molding cycle time.

Although the injection device 300 of the present embodiment is of the in-line screw method, it may be of the pre-plastic method or the like. A pre-plastic injection apparatus supplies molding material melted in a plasticizing cylinder to an injection cylinder, and injects the molding material from the injection cylinder into a mold apparatus. Inside the plasticizing cylinder, a screw is arranged to be rotatable and non-retractable, or a screw is arranged to be rotatable and reciprocal. On the other hand, a plunger is arranged in the injection cylinder so that it can move back and forth.

Further, the injection device 300 of the present embodiment is a horizontal type in which the axial direction of the cylinder 310 is horizontal, but may be a vertical type in which the axial direction of the cylinder 310 is vertical. The mold clamping device combined with the vertical injection device 300 may be either vertical or horizontal. Similarly, the mold clamping device combined with the horizontal injection device 300 may be horizontal or vertical.

(moving device)
In the description of the moving device 400, as in the description of the injection device 300, the axial direction of the screw 330 during filling (for example, the negative direction of the X-axis) is defined as the front, and the axial direction of the screw 330 during weighing (eg, the positive direction of the X-axis). is described as backward.

The moving device 400 advances and retreats the injection device 300 with respect to the mold device 800 . Further, the moving device 400 presses the nozzle 320 against the mold device 800 to generate nozzle touch pressure. The moving device 400 includes a hydraulic pump 410, a motor 420 as a drive source, a hydraulic cylinder 430 as a hydraulic actuator, and the like.

The hydraulic pump 410 has a first port 411 and a second port 412 . Hydraulic pump 410 is a pump that can rotate in both directions, and by switching the rotation direction of motor 420, hydraulic fluid (for example, oil) is sucked from one of first port 411 and second port 412 and discharged from the other. to generate hydraulic pressure. Note that the hydraulic pump 410 can also suck the working fluid from the tank and discharge the working fluid from either the first port 411 or the second port 412 .

The motor 420 operates the hydraulic pump 410 . Motor 420 drives hydraulic pump 410 with a rotational direction and rotational torque according to a control signal from control device 700 . Motor 420 may be an electric motor or may be an electric servomotor.

The hydraulic cylinder 430 has a cylinder body 431 , a piston 432 and a piston rod 433 . The cylinder body 431 is fixed with respect to the injection device 300 . The piston 432 partitions the inside of the cylinder body 431 into a front chamber 435 as a first chamber and a rear chamber 436 as a second chamber. Piston rod 433 is fixed relative to stationary platen 110 .

The front chamber 435 of the hydraulic cylinder 430 is connected to the first port 411 of the hydraulic pump 410 via the first flow path 401 . The hydraulic fluid discharged from the first port 411 is supplied to the front chamber 435 through the first flow path 401, thereby pushing the injection device 300 forward. The injection device 300 is advanced and the nozzle 320 is pressed against the stationary mold 810 . The front chamber 435 functions as a pressure chamber that generates nozzle touch pressure of the nozzle 320 by the pressure of the hydraulic fluid supplied from the hydraulic pump 410 .

On the other hand, the rear chamber 436 of the hydraulic cylinder 430 is connected to the second port 412 of the hydraulic pump 410 via the second flow path 402 . The hydraulic fluid discharged from the second port 412 is supplied to the rear chamber 436 of the hydraulic cylinder 430 through the second flow path 402, thereby pushing the injection device 300 rearward. The injection device 300 is retracted and the nozzle 320 is separated from the stationary mold 810 .

Although the moving device 400 includes the hydraulic cylinder 430 in this embodiment, the present invention is not limited to this. For example, instead of the hydraulic cylinder 430, an electric motor and a motion conversion mechanism that converts the rotary motion of the electric motor to the linear motion of the injection device 300 may be used.

(Control device)
The control device 700 is composed of, for example, a computer, and has a CPU (Central Processing Unit) 701, a storage medium 702 such as a memory, an input interface 703, and an output interface 704, as shown in FIGS. The control device 700 performs various controls by causing the CPU 701 to execute programs stored in the storage medium 702 . The control device 700 also receives signals from the outside through an input interface 703 and transmits signals to the outside through an output interface 704 .

The control device 700 repeatedly performs a weighing process, a mold closing process, a pressurizing process, a mold clamping process, a filling process, a holding pressure process, a cooling process, a depressurizing process, a mold opening process, and an ejecting process, thereby producing a molded product. Repeat production. A series of operations for obtaining a molded product, for example, the operation from the start of the weighing process to the start of the next weighing process, is also called "shot" or "molding cycle". The time required for one shot is also called "molding cycle time" or "cycle time".

A single molding cycle has, for example, a weighing process, a mold closing process, a pressurization process, a mold clamping process, a filling process, a holding pressure process, a cooling process, a depressurization process, a mold opening process, and an ejection process in this order. The order here is the order of the start of each step. The filling process, holding pressure process, and cooling process are performed during the clamping process. The start of the clamping process may coincide with the start of the filling process. Completion of the depressurization process coincides with the start of the mold opening process.

In addition, multiple processes may be performed at the same time for the purpose of shortening the molding cycle time. For example, the metering step may occur during the cooling step of the previous molding cycle and may occur during the clamping step. In this case, the mold closing process may be performed at the beginning of the molding cycle. The filling process may also be initiated during the mold closing process. Also, the ejecting process may be initiated during the mold opening process. If an on-off valve for opening and closing the flow path of the nozzle 320 is provided, the mold opening process may be initiated during the metering process. This is because the molding material does not leak from the nozzle 320 as long as the on-off valve closes the flow path of the nozzle 320 even if the mold opening process is started during the metering process.

One molding cycle includes processes other than the weighing process, mold closing process, pressurizing process, mold clamping process, filling process, holding pressure process, cooling process, depressurizing process, mold opening process, and ejecting process. may

For example, after the pressure holding process is completed, a pre-measuring suck-back process may be performed in which the screw 330 is retracted to a preset measuring start position before starting the measuring process. It is possible to reduce the pressure of molding material accumulated in front of the screw 330 before the start of the metering process, and to prevent the screw 330 from abrupt retraction at the start of the metering process.

Also, after the weighing process is completed and before the filling process starts, a post-weighing suck-back process may be performed in which the screw 330 is retracted to a preset filling start position (also referred to as an "injection start position"). The pressure of the molding material accumulated in front of the screw 330 before the start of the filling process can be reduced, and leakage of the molding material from the nozzle 320 before the start of the filling process can be prevented.

The control device 700 is connected to an operation device 750 that receives user input operations and a display device 760 that displays screens. The operation device 750 and the display device 760 may be configured by, for example, a touch panel 770 and integrated. A touch panel 770 as a display device 760 displays a screen under the control of the control device 700 . Information such as the settings of the injection molding machine 10 and the current state of the injection molding machine 10 may be displayed on the screen of the touch panel 770 . Further, on the screen of the touch panel 770, for example, an operation unit such as a button for receiving an input operation by the user or an input field may be displayed. A touch panel 770 as the operation device 750 detects an input operation on the screen by the user and outputs a signal corresponding to the input operation to the control device 700 . As a result, for example, the user can operate the operation unit provided on the screen while confirming the information displayed on the screen to set the injection molding machine 10 (including input of set values). can. Further, the user can operate the operation unit provided on the screen to cause the injection molding machine 10 to operate corresponding to the operation unit. The operation of the injection molding machine 10 may be, for example, the operation (including stopping) of the mold clamping device 100, the ejector device 200, the injection device 300, the moving device 400, and the like. Also, the operation of the injection molding machine 10 may be switching of screens displayed on the touch panel 770 as the display device 760 .

Although the operating device 750 and the display device 760 of the present embodiment are described as being integrated as the touch panel 770, they may be provided independently. Also, a plurality of operating devices 750 may be provided. The operating device 750 and the display device 760 are arranged on the operating side (Y-axis negative direction) of the mold clamping device 100 (more specifically, the stationary platen 110).

(details of injection unit)
FIG. 3 is a diagram showing a state at the start of injection of the injection device according to one embodiment. FIG. 4 is a diagram showing a state of the injection device according to one embodiment when injection is completed. 5 is a partially enlarged view of FIG. 4. FIG. The injection device 300 has an injection device main body 303 and a support frame 304 that supports the injection device main body 303 . The injection device main body 303 includes, for example, a cylinder 310, a nozzle 320, a screw 330, a metering motor 340, an injection motor 350, and a load detector 360. The injection device main body 303 further includes a bearing 361 that rotatably supports the screw 330, a drive shaft 362 that is moved forward and backward while being rotated by the injection motor 350, and a drive shaft 362 that is rotatably supported via the bearing 361. and a bearing holder 370 .

The support frame 304 is installed on the slide base 301 . The slide base 301 advances and retreats along two guides 302 (only one guide is shown in FIGS. 3 and 4). Two guides 302 are laid on the injection unit frame 920 . The two guides 302 each extend in the X-axis direction. The two guides 302 are spaced apart in the Y-axis direction. The support frame 304 is installed on the slide base 301 so as to be rotatable around a vertical pivot 304Z. The injection device main body 303 can be pivoted together with the support frame 304 .

The support frame 304 has a front pivot plate 305 and a rear pivot plate 306 . The front swivel plate 305 and the rear swivel plate 306 are slidably mounted on the upper surface of the slide base 301 . A swivel shaft 304Z is arranged at a predetermined position of the front swivel plate 305 . A rear pivot plate 306 is arranged behind the front pivot plate 305 .

The support frame 304 has a front flange 307 , a rear flange 308 and multiple connecting rods 309 . A front flange 307 is attached to the front pivot plate 305 . A rear flange 308 is attached to the rear pivot plate 306 . A connecting rod 309 connects the front flange 307 and the rear flange 308 with a space therebetween.

A cylinder 310 and a metering motor 340 are attached to the front flange 307 . Cylinder 310 is arranged in front of front flange 307 and attached to front flange 307 via cylinder 315 . A metering motor 340 is located behind the front flange 307 and forward of the rear flange 308 .

On the other hand, an injection motor 350 is attached to the rear flange 308 . The injection motor 350 is arranged behind the rear flange 308 and attached to the rear flange 308 via a load detector 360 which will be described later.

The metering motor 340 rotates the screw 330 . The metering motor 340 has a stator 342 fixed to the front flange 307, a rotor 343 rotating inside the stator 342, and bearings 349 supporting the rotor 343 for rotation. Stator 342 includes a front flange 342a holding bearing 349, a rear flange 342b holding bearing 349, and a housing 342c connecting front flange 342a and rear flange 342b. Rotational motion of metering motor 340 is transmitted to bearing holder 370 and from bearing holder 370 to screw 330 .

The bearing holder 370 has a screw mounting portion 372 to which the screw 330 is mounted, and a metering spline shaft 371 to which the rotor 343 of the metering motor 340 is splined. The metering spline shaft 371 is arranged inside the rotor 343 of the metering motor 340 . A metering spline nut 344 is provided on the rotor 343 .

The metering spline nut 344 has a plurality of key grooves arranged at equal intervals in the circumferential direction on its inner peripheral surface. On the other hand, the metering spline shaft 371 has a plurality of keys arranged at equal intervals in the circumferential direction on its outer peripheral surface. The metering spline shaft 371 and the metering spline nut 344 are splined together. Note that the number of key grooves and the number of keys may be one.

The injection motor 350 moves the screw 330 forward and backward. The injection motor 350 includes a stator 352 fixed to the rear flange 308 via a load detector 360, a rotor 353 rotating inside the stator 352, and bearings 359 rotatably supporting the rotor 353. and have The rotary motion of the injection motor 350 is converted into rotary linear motion of the drive shaft 362 and further into linear motion of the bearing holder 370 . As the bearing holder 370 advances and retreats, the screw 330 advances and retreats.

The drive shaft 362 has an injection spline shaft 363, a screw shaft 364, and a rotary shaft 365 in this order on the same straight line from the rear side toward the front.

The injection spline shaft 363 is arranged inside the rotor 353 of the injection motor 350 . The rotor 353 is provided with an injection spline nut 354 . The injection spline nut 354 has a plurality of key grooves arranged at equal intervals in the circumferential direction on its inner peripheral surface. On the other hand, the injection spline shaft 363 has a plurality of keys arranged at equal intervals in the circumferential direction on its outer peripheral surface. The injection spline shaft 363 and the injection spline nut 354 are spline-coupled. Note that the number of key grooves and the number of keys may be one.

The screw shaft 364 is screwed with a screw nut 366 . Balls or rollers may be interposed between the threaded shaft 364 and the threaded nut 366 . The threaded nut 366 is fixed to the rear flange 308 via the load detector 360 so that it does not rotate with the threaded shaft 364 . Therefore, the screw shaft 364 advances and retreats while rotating. The injection spline shaft 363 and the injection spline nut 354 are spline-coupled so that the screw shaft 364 can advance and retreat while rotating.

A rotating shaft 365 is held by a bearing holder 370 via a bearing 361 . The bearing holder 370 has a cylindrical metering spline shaft 371 , and a bearing 361 is fixed to the inner peripheral surface of the metering spline shaft 371 . Bearing 361 has an inner ring that rotates with rotating shaft 365 and an outer ring that is fixed relative to metering spline shaft 371 . The bearing 361 prevents transmission of rotational driving force from the rotating shaft 365 to the bearing holder 370 .

As the rotating shaft 365 advances and retreats while rotating, the bearing holder 370 advances and retreats, and the screw 330 advances and retreats. The metering motor 340 does not advance or retreat when the screw 330 advances or retreats. This is because the metering spline nut 344 of the metering motor 340 and the metering spline shaft 371 of the bearing holder 370 are spline-coupled. Since the metering motor 340 is not included in the driving target of the injection motor 350, the inertia of the driving target of the injection motor 350 is small, and the acceleration of the screw 330 when starting to move forward is fast.

The structure of the injection device 300 is not limited to the structure shown in FIGS. 3 and 4. For example, the arrangement of the drive source (for example, the metering motor 340 and the injection motor 350) that drives the screw 330 is not limited to the arrangement shown in FIGS. Specifically, in this embodiment, the rotation center line of the screw 330, the rotation center line of the metering motor 340, and the rotation center line of the injection motor 350 are arranged on the same straight line, but they are arranged on the same straight line. It doesn't have to be.

Also, the structure of the transmission mechanism that transmits the driving force of the drive source to the screw 330 is not limited to the structure shown in FIGS. The structure of the transmission mechanism is changed as appropriate according to the arrangement of the drive source that drives the screw 330 . For example, a timing belt may be used when the parallel centerline of rotation of the metering motor 340 and the centerline of rotation of the screw 330 are offset in a direction orthogonal to these centerlines. Similarly, when the rotation centerlines of the injection motor 350 and the screw 330, which are parallel to each other, are offset in a direction orthogonal to these rotation centerlines, a timing belt may be used.

A coupling 375 connects the screw 330 and the bearing holder 370 . The coupling 375 has a spline nut 376 to which the spline shaft 332 formed at the rear end of the screw 330 is spline-coupled, and a flange 377 that presses the spline shaft 332 from the front. Flange 377 fits into groove 333 of screw 330 . A groove 333 is formed in front of the spline shaft 332 . The flange 377 is divided into two arc-shaped split bodies, which are fitted into the grooves 333 and press the spline shaft 332 from the front.

The flange 377 is fastened to the spline nut 376 with a first bolt 378. The spline nut 376 is fastened to the bearing holder 370 by a second bolt 379 and presses the load detector 360 from the front. The operation of tightening and loosening the first bolt 378 and the second bolt 379 is performed through the window 316 of the cylinder 315 located between the front flange 307 and the cooler 312 .

The tubular body 315 includes a tubular portion 315a protruding forward from the front flange 307 and an inner flange portion 315b protruding inside the tubular portion 315a from the front end surface of the tubular portion 315a. A window 316 is formed in the cylindrical portion 315a. The outer edge of the cylinder 310 is fixed to the inner edge of the inner flange portion 315b.

An annular groove into which the annular packing 381 is fitted and an annular groove into which the slide ring 382 is fitted are formed on the outer peripheral surface of the bearing holder 370 .

The annular packing 381 is held by, for example, the bearing holder 370, slidably contacts the rotor 343 of the metering motor 340, and seals the gap between the rotor 343 and the bearing holder 370. This can prevent the lubricant supplied to the metering spline shaft 371 from leaking to the screw 330 side.

The annular packing 381 may be attached to the metering spline shaft 371 in front of the key 371a of the metering spline shaft 371, and may be attached to the metering spline shaft 371. However, as shown in FIGS. good.

As the annular packing 381, for example, an O-ring having a circular cross-sectional shape is used, and is used after being moderately compressed. The annular packing 381 is made of a softer material than the slide ring 382 in order to ensure sealing performance. Examples of the material of the annular packing 381 include rubber such as butyl rubber.

Although the annular packing 381 is held by the bearing holder 370 in this embodiment, the annular packing 381 is held by the rotor 343 of the metering motor 340 and slidably contacts the bearing holder 370 so that the rotor 343 and the screw mounting portion 372 are held. You may seal the gap between

The slide ring 382 is held by, for example, the screw mounting portion 372 and slidably contacts the rotor 343 of the metering motor 340 to align the center line of the rotor 343 with the center line of the screw mounting portion 372 . As a result, galling between the rotor 343 and the screw mounting portion 372 can be suppressed. Also, it is possible to suppress the application of an unbalanced load to the annular packing 381 .

The slide ring 382 is made of a harder material than the annular packing 381 in order to suppress eccentricity between the rotor 343 and the screw mounting portion 372 . As a material for the slide ring 382, a crystalline resin or the like having high self-lubricating properties is used. Examples of crystalline resins include polytetrafluoroethylene (PTFE), polyamide (PA), polyesters (PEs), and polyethylene (PE). The greater the degree of crystallinity, the greater the self-lubricating properties. The slide ring 382 may be made of resin other than crystalline resin, for example, it may be made of cloth-filled phenolic resin.

Unlike the annular packing 381, the slide ring 382 does not ensure sealing performance, so it has a cut partly in the circumferential direction. The cut is formed for attachment and detachment of the slide ring 382 , is widened during attachment and detachment, and then restored by the elastic restoring force of the slide ring 382 .

Although the slide ring 382 is held by the screw mounting portion 372 in this embodiment, it is held by the rotor 343 of the weighing motor 340 and is slidably brought into contact with the screw mounting portion 372 to move the center line of the rotor 343. and the center line of the screw mounting portion 372 may be aligned. Also, the number of slide rings 382 may be plural.

As shown in FIGS. 3 to 5, a slide ring 382 and an annular packing 381 are arranged in this order from the key 371a side (rear side) of the metering spline shaft 371 toward the screw 330 side (front side). there is The annular packing 381 prevents the lubricant supplied to the metering spline shaft 371 and passed through the slide ring 382 from leaking to the screw 330 side. By supplying the lubricant to the slide ring 382, the sliding resistance of the slide ring 382 can be reduced, and leakage of the lubricant to the screw 330 side can be suppressed. Here, the lubricant supplied to the metering spline shaft 371 is formed between the slide ring 382 and the rotor 343 of the metering motor 340, between the slide ring 382 and the screw mounting portion 372, and in the slide ring 382. pass through gaps, etc.

The injection molding machine 10 includes a load detector 360. Load detector 360 detects the load transmitted between injection motor 350 and screw 330 . A load detector 360 detects a load behind the bearing 361 . A load detector 360 , for example of the washer type, is located between the rear flange 308 and the injection motor 350 .

The load detected by the load detector 360 includes the sliding resistance of mechanical elements and the like. The sliding resistance of the mechanical elements includes, for example, the sliding resistance between the outer ring and the inner ring of the bearing 361, the sliding resistance between the screw shaft 364 and the screw nut 366, and the sliding resistance between the injection spline shaft 363 and the injection spline nut 354. resistance and sliding resistance between metering spline shaft 371 and metering spline nut 344 .

FIG. 6 is a diagram showing functional blocks of components of the control device 700 according to one embodiment. Each functional block illustrated in FIG. 6 is conceptual and does not necessarily need to be physically configured as illustrated. All or part of each functional block can be functionally or physically distributed and integrated in arbitrary units. Each processing function performed by each functional block is implemented by a program executed by the CPU 701, in whole or in part. Alternatively, each functional block may be implemented as hardware by wired logic. As shown in FIG. 6, the control device 700 includes a correction information storage unit 601, an acquisition unit 602, a registration unit 603, a correction control unit 604, a display control unit 605, and a pressure control unit 606. The correction information storage unit 601 stores information for correcting the pressure detection value detected by the load detector 360 based on the speed of the screw 330, the axial phase of the screw 330, and the phase of the weighing motor 340. . The acquisition unit 602 acquires various information such as the pressure detection value detected by the load detector 360 . The registration unit 603 registers information for correction in the correction information storage unit 601 based on the information acquired by the acquisition unit 602 . The correction control unit 604 corrects the detection value detected by the load detector 360 based on the information stored in the correction information storage unit 601 and corrects the pressure set value used for pressure control of the screw 330 . The display control unit 605 displays the corrected pressure value on the display device 760 . A pressure control unit 606 performs pressure control based on the corrected pressure set value. A specific description of each configuration will be given later.

Next, the operation of the injection molding machine 10 will be explained.

In the weighing process, the weighing motor 340 rotates and the screw 330 rotates. Then, the flight (thread) of the screw 330 moves, and the resin pellets (solid molding material) filled in the thread groove of the screw 330 are sent forward. The resin pellets are gradually melted by being heated by heat from heaters 313_1 to 313_5 via cylinder 310 while moving forward in cylinder 310 . Then, the resin pellets are completely melted at the tip of the cylinder 310 . Then, as the liquid molding material (resin) is fed forward of the screw 330 and accumulated in the front portion of the cylinder 310, the screw 330 retreats.

The weighing motor encoder 341 detects rotation of the weighing motor 340 and transmits a signal indicating the detection result to the control device 700 . The screw rotation speed detector that detects the rotation speed of the screw 330 is not limited to the weighing motor encoder 341, and a general one can be used.

　Conventionally, the friction and unbalanced load inside the injection device 300 acted on the load detector 360. In the injection device 300, the pressure detected by the load detector 360 was tested when the screw 330 was not mounted. It was found that there was a change in the detected value of

Due to these factors, even if the detected value detected by the load detector 360 is the same, the actual pressure applied to the resin may change from moment to moment or may vary from shot to shot.

FIG. 7 is a conceptual diagram showing the pressure detected by the load detector 360 during weighing in this embodiment. In the example shown in FIG. 7, the forces applied during weighing are indicated by arrows. For example, the detected value 1701 is the pressure detected by the load detector 360 . By the way, the load detector 360 is desired to detect the force 1702 due to the resin pressure. However, friction and uneven load inside the injection molding machine 10 affect the load detector 360 . Therefore, the detected value 1701 is expressed by the following formula (1).

Detected value 1701 = Force due to resin pressure 1702 - First sliding resistance 1703 - Second sliding resistance 1706 + Moment 1704 of metering spline shaft 371 + Moment 1705 of injection spline shaft 363 ... (1)

The moment 1704 of the metering spline shaft 371 and the moment 1704 of the metering spline shaft 371 shown in equation (1) are included in the detected value 1701 because the load detector 360 also detects a torsional force. .

The first sliding resistance 1703 is, for example, sliding resistance due to the metering spline shaft 371, the annular packing 381, and the slide ring 382. The sliding resistance of the metering spline shaft 371 is generated at the spline joint between the metering spline nut 344 and the metering spline shaft 371 . When the metering spline shaft 371 is eccentric, the contact area of the metering spline shaft 371 with the metering spline nut 344 changes according to the phase of the metering spline shaft 371 . Therefore, the sliding resistance changes according to the phase of the metering spline shaft 371 . By the way, the metering spline shaft 371 is coupled with the screw 330 via the bearing holder 370 . Therefore, in other words, the first sliding resistance 1703 changes according to the circumferential position (rotational angle) of the screw 330 .

A second sliding resistance 1706 is a sliding resistance due to the injection spline shaft 363 . In other words, the sliding resistance of the second sliding resistance 1706 is generated at the spline-connected locations among the metering spline nut 344 , injection spline shaft 363 , and injection spline nut 354 . When the injection spline shaft 363 is eccentric, the area of the injection spline shaft 363 in contact with the injection spline nut 354 changes according to the phase of the injection spline shaft 363 . Therefore, the second sliding resistance 1706 changes according to the phase of the injection spline shaft 363 . The injection spline shaft 363 is connected to the injection motor 350 . The injection motor 350 is used for movement control of the position of the screw 330 in the axial direction. Therefore, in other words, the second sliding resistance 1706 changes according to the axial position of the screw 330 (the phase of the injection motor 350).

Thus, when generating a correction value for detecting the force 1702 due to the resin pressure, it is necessary to change it based on the circumferential position (rotational angle) of the screw 330 and the axial position of the screw 330 . In the example shown in FIG. 7, the force at the time of weighing is shown, but the force at the time of filling and holding pressure can also be calculated by the same method, and the explanation is omitted.

FIG. 8 is a diagram illustrating the relationship between the value detected by the load detector 360 and the force due to the resin pressure according to the first embodiment. In the example shown in FIG. 8, the value 1801 detected by the load detector 360 during weighing and the resistance 1802 due to mechanical friction or the like during weighing are used. The resistance force 1802 includes, in addition to the sliding resistances described above (eg, the first sliding resistance 1703 and the second sliding resistance 1706), a moment (eg, the moment 1704 of the metering spline shaft 371 and the injection spline The moment 1704) of axis 363 is also included.

Since the screw 330 retreats during weighing, when the direction of the detection value 1801 detected by the load detector 360 (for example, the direction of the detection value 1701) is set to the positive direction, the resistance 1802 due to mechanical friction or the like during weighing acts in the negative direction. Then, the force 1803 due to the resin pressure during weighing can be derived from the detection value 1801 - resistance force 1802 .

In the example shown in FIG. 8, the value 1804 detected by the load detector 360 during filling/holding pressure is taken as the resistance force 1805 due to mechanical friction or the like during filling/holding pressure. The resistance force 1805 includes a moment in addition to the sliding resistance described above.

Since the screw 330 advances during filling and holding pressure, when the direction of the detection value 1801 detected by the load detector 360 is positive, the resistance 1805 due to mechanical friction and the like during filling and holding pressure is positive. direction. A force 1806 due to the resin pressure during filling/holding can be derived from the detection value 1804 - resistance force 1805 .

As shown in FIG. 8, the force 1803 due to the resin pressure during metering is smaller than the force 1806 due to the resin pressure during filling/holding. In other words, fluctuations such as mechanical friction act greatly. The control device 700 of the present embodiment achieves highly accurate detection even of the force 1803 due to the resin pressure during measurement.

Specifically, the correction information storage unit 601 stores in advance a table for identifying a correction value from a combination of the variables of the circumferential position of the screw 330, the position of the screw 330, and the speed of the screw. back. Then, the correction control unit 604 acquires the correction value from the table in real time and corrects the pressure detection value detected by the load detector 360 . Since it is considered that there are individual differences for each injection apparatus 300, it is conceivable that the correction values are registered in the table during an inspection process before shipment or when the user starts molding.

Returning to FIG. 6, the acquisition unit 602 acquires the pressure detection value detected by the load detector 360 .

The registration unit 603 registers a correction value (an example of correction information) obtained by correcting the detection value of the load detector 360 in the correction information storage unit 601 based on the acquired pressure detection value. The correction value of the present embodiment is a value representing a force (resisting force) generated by disturbance due to mechanical friction or the like. Then, in this embodiment, the force due to the resin pressure can be derived by subtracting the correction value from the detected value.

FIG. 9 is a diagram showing detection values detected by the load detector 360 when the position of the screw 330 (the phase of the injection spline shaft 363) is moved while the position of the screw 330 in the circumferential direction is fixed. In the example shown in FIG. 9, the variation 901 of the detected value when the circumferential position (rotation angle) of the screw 330 is fixed at the initial position, and the circumferential position (rotation angle) of the screw 330 is fixed at +90°. variation 902 in the detected value when the position (rotation angle) of the screw 330 is fixed at +180°; variation 903 in the detection value when the position (rotation angle) of the screw 330 in the circumferential direction is fixed at +270°; and a variation 904 of the detected value when fixed at .

Then, according to the

fluctuations

901 and 904 of the detected values, it can be confirmed that the detected pressure values change periodically according to the position of the screw 330 . A change in this detected value corresponds to a change in the phase (rotational angle) of the injection spline shaft 363 .

Similarly, the detected pressure value changes according to the circumferential position (rotational angle) of the screw 330 . Furthermore, the detected pressure value changes according to the speed of the screw 330 .

Therefore, in the present embodiment, based on the circumferential position (rotation angle) of the screw 330, the axial position of the screw 330 (the phase of the injection spline shaft 363), and the speed of the screw 330, Correct the detected value.

In this embodiment, a method is used in which a table in which correction values are stored is created in advance. In this embodiment, in order to create the correction information storage unit 601 storing the correction values, the pressure is detected by the load detector 360 in the injection apparatus 300 in a state where the assembly of the screw 330 is not mounted. The assembly of the screw 330 may include, for example, the screw 330 , the cylindrical body 315 , the cylinder 310 and the nozzle 320 . The environment in which the pressure is detected is not limited to when the screw 330 is not mounted on the assembly.

The registration unit 603 registers the pressure detection value detected by the load detector 360 in the correction information storage unit 601 as a correction value.

FIG. 10 is a diagram exemplifying a table of the correction information storage unit 601 registered in the registration unit 603 according to this embodiment. As shown in FIG. 10, the table of the correction information storage unit 601 of the present embodiment includes the axial position of the screw 330 (the phase of the injection spline shaft 363), the circumferential position (rotation angle) of the screw 330, and the A correction value (force due to resin pressure) can be specified by a combination of the speeds of the screws 330 . In the example shown in FIG. 10, a table is created for each speed of the screw 330, and the speed of the screw 330 is V ₁ <V ₂ <V ₃ <maximum speed.

Then, the correction control unit 604 refers to the correction information storage unit 601 to obtain a correction value based on the circumferential position of the screw 330, the axial position of the screw 330, and the speed of the screw. is corrected based on the correction value, and the corrected detection value is specified.

The display control unit 605 displays the detected value corrected by the correction control unit 604 on the display device 760 as a force due to the resin pressure.

The pressure control unit 606 performs pressure control so that the detected value corrected by the correction control unit 604 becomes a preset pressure setting value for filling the injection device 300 with the molding material when the mold is closed. . As a result, the influence of disturbances such as sliding resistance and moment can be eliminated, so the accuracy of pressure control can be improved.

FIG. 11 is a flowchart for registering correction values in the correction information storage unit 601 in the control device 700 according to this embodiment. When the correction values shown in FIG. 11 are registered, the assembly of the screw 330 is not mounted.

First, the registration unit 603 of the control device 700 performs initial settings (S1101). In the initial setting, the axial position of the screw 330 (the phase of the injection spline shaft 363) and the circumferential position (rotational angle) of the screw 330 are set to initial positions (for example, "0"), and the speed of the screw 330 is set to Set to initial speed.

Next, the registration unit 603 performs stroke control of the screw 330 from the initial position (for example, "0") to the maximum value at the set speed (S1102).

The acquisition unit 602 acquires the detection value detected by the load detector 360 during stroke control (S1103).

The registration unit 603 associates the correction value corresponding to the detection value acquired by the acquisition unit 602 with the axial position of the screw 330, the speed of the screw 330, and the circumferential position when the detection value is detected. are registered in the correction information storage unit 601 (S1104).

The registration unit 603 determines whether correction values have been registered for all positions of the screw 330 in the circumferential direction at the current speed of the screw 330 (S1105).

When the registration unit 603 determines that correction values have not been registered for all positions of the screw 330 in the circumferential direction (S1105: No), the position of the screw 330 in the circumferential direction is changed (S1106). In this embodiment, the position of the screw 330 in the circumferential direction is changed in order of 0°, 90°, 180° and 270°. After that, the process is performed again from S1102.

On the other hand, if the registration unit 603 determines that correction values have been registered for all circumferential positions of the screw 330 (S1105: Yes), has the registration unit 603 registered correction values for all velocities of the screw 330? It is determined whether or not (S1107).

When the registration unit 603 determines that correction values have not been registered for all the speeds of the screw 330 (S1107: No), it changes the speed of the screw 330 (S1108). Note that the speed of the screw 330 is changed based on the operation of the injection motor 350 .

On the other hand, if the registration unit 603 determines that correction values have been registered for all velocities of the screw 330 (S1108: Yes), the process ends.

Registration of the correction value in the correction information storage unit 601 is completed by the above-described processing procedure.

Next, the display control during weighing will be explained. FIG. 12 is a flowchart of display processing during weighing in the control device 700 according to the present embodiment.

First, the acquisition unit 602 acquires the pressure value detected by the load detector 360 during stroke control (S1201). Furthermore, the acquisition unit 602 obtains the current speed of the screw 330, the circumferential position , and the axial position of the screw 330 (S1202).

Next, the correction control unit 604 refers to the correction information storage unit 601 to obtain correction values associated with the speed of the screw 330, the circumferential position of the screw 330, and the axial position of the screw 330. (S1203).

Then, the correction control unit 604 derives a corrected detection value by subtracting the correction value from the detection value.

The display control unit 605 displays the corrected detection value on the display device 760 as the force due to the resin pressure (S1204).

In this embodiment, by performing the above-described processing procedure, it is possible to detect the force due to the resin pressure while suppressing the influence of disturbance such as mechanical friction during weighing.

Also, in the example shown in FIG. 12, the method of detecting the force due to the resin pressure based on the value detected by the load detector 360 during weighing has been described. However, the detection of force due to resin pressure is not limited to weighing. For example, the force due to the resin pressure may be detected based on the value 804 detected by the load detector 360 during filling/holding.

At the time of filling and holding pressure, the pressure control unit 606 performs pressure control so that the correction value acquired by the correction control unit 604 becomes a preset pressure set value for filling the injection device 300 with the molding material. I do.

Further, in the present embodiment, an example of correcting the detection value by the load detector 360 with reference to the correction information storage unit 601 has been described. However, this embodiment does not limit the correction target to the detected value, and may correct the pressure setting for performing pressure control.

In this case, the correction information storage unit 601 stores pressure setting values associated with the speed of the screw 330, the position of the screw 330 in the circumferential direction, and the position of the screw 330 in the axial direction. Then, the pressure control unit 606 performs pressure control so that the detection value acquired by the acquisition unit 602 becomes a pressure setting value set in consideration of disturbance such as mechanical resistance.

(Second embodiment)
In the above-described embodiment, the method of identifying the correction value with reference to the table held by the correction information storage unit 601 has been described. However, the first embodiment is not limited to the method of customizing the correction values only with the table held by the correction information storage unit 601 . Therefore, in the second embodiment, a method of specifying a correction value by combining a mathematical model and a table will be described.

As shown in Figure 9, etc., the force caused by the disturbance changes periodically. For example, according to the detected

value fluctuations

901 and 904 , the detected pressure value periodically changes according to the position of the screw 330 . A change in this detected value corresponds to a change in the phase (rotational angle) of the injection spline shaft 363 . Similarly, the change in detected value occurs in response to the phase change of the metering spline shaft 371 . Therefore, by forming a mathematical model of the periodic change of each element, a correction value corresponding to the disturbance element can be specified from the mathematical model.

FIG. 13 is a diagram illustrating the resistance (including friction) that changes according to the circumferential position (rotation angle) of the screw 330 or the axial position of the screw 330 (phase of the injection spline shaft 363). As described above, the resistance fluctuation 1301 changes periodically according to the circumferential position (rotational angle) of the screw 330 or the axial position of the screw 330 (phase of the injection spline shaft 363).

Therefore, a sine function 1002 corresponding to the resistance variation 1301 including friction and the like can be derived. In this case, the following formula (2) can be derived. It should be noted that the phase θ _offset is a phase offset corresponding to the actual friction fluctuation of the injection device 300 . The variable k is assumed to be a coefficient corresponding to the variation width of the actual injection device 300 . The phase θ is the circumferential position (rotational angle) of the screw 330 or the phase of the injection spline shaft 363 that moves the position of the screw 330 .

Correction value for each element = k·sin ² ((θ-θ _offset )/2)……(2)

Then, by combining a formula representing a correction value corresponding to the circumferential position (rotation angle) of the screw 330 and a formula representing a correction value corresponding to the phase of the injection spline shaft 363 that moves the position of the screw 330, , it is possible to derive a formula capable of calculating a correction value for the position (hereinafter also referred to as a position correction value). A formula model for calculating the correction value can be realized by combining a formula capable of calculating the correction value for the position and a correction value corresponding to the speed of the screw 330 (hereinafter referred to as speed correction value).

Specifically, the registration unit 603 registers each value (k, θ _{ij_offset} , θ _{rt_offset} , and a table of speed correction values Pv) of Equation (3) below in the correction information storage unit 601 . The variable k is assumed to be a coefficient corresponding to the variation width of the actual injection device 300 . The phase θ _ij is the phase of the injection motor 350 (injection spline shaft 363) that moves the screw 330 in the axial direction. The correspondence relationship between the phase θ _ij (angle) of the injection motor 350 and the position of the screw 330 can be derived from the correspondence relationship between the rotation angle of the injection motor 350 and the amount of movement of the screw 330, and the description thereof is omitted. The phase θ _rt is the circumferential position (rotational angle) of the screw 330 . The phase θ _{ij_offset} is a phase offset according to the variation of the actual axial position of the screw 330 (the phase of the injection motor 350). The phase θ _{rt_offset} is a phase offset that corresponds to the variation of the actual circumferential position (rotational angle) of the screw 330 . A table of speed correction values Pv corresponding to the speed of the screw 330 will be described later.

Correction value = Pv・k・sin ² ((θ _ij −θ _{ij_offset} )/2)・sin ² ((θ _rt −θ _{rt_offset} )/2)……(3)

FIG. 14 is a diagram showing the structure of the speed correction value storage table held by the correction information storage unit 601 according to this embodiment. As shown in FIG. 14, the speed correction value Pv is stored in association with the axial speed of the screw 330 .

Note that the speed correction value Pv and the variable k are set to the axial position of the screw 330 while varying the speed and circumferential position of the screw 330 as shown in the flowchart of FIG. 11 of the first embodiment. The description is omitted as it is specified by acquiring the detection value for each. Note that the period of the phase θ _ij and the phase θ _{ij_offset} can be derived from the period and phase of the injection motor 350 . Similarly, the period of phase θ _rt and phase θ _{rt_offset} can be derived from the period and phase of metering motor 340 . Thereby, the correction value can be derived based on the equation (3).

FIG. 15 is a diagram exemplifying variations in correction values calculated by the correction control unit 604 using equation (3).

Cycles

1551 , 1552 , 1553 , 1554 , and 1555 in FIG. 15 indicate rotation cycles of the injection motor 350 .

In the example shown in FIG. 15, the correction value variation 1501 corresponds to the detected value variation 901 when the circumferential position (rotational angle) of the screw 330 is the initial position. Further, the correction value variation 1502 corresponds to the detection value variation 902 when the circumferential position (rotation angle) of the screw 330 is +90°. Further, the correction value variation 1503 corresponds to the detection value variation 903 when the circumferential position (rotational angle) of the screw 330 is +180°. Further, the correction value variation 1504 corresponds to the detection value variation 904 when the circumferential position (rotational angle) of the screw 330 is +270°.

As described above, the correction control unit 604 of the present embodiment stores the parameter and speed correction value storage table stored in the correction information storage unit 601, the circumferential position of the screw 330, the axial position of the screw 330, and the A correction value is calculated from equation (3) using the velocity and .

Then, the correction control unit 604 subtracts the calculated correction value from the detection value acquired by the acquisition unit 602 to derive a corrected detection value. Subsequent processing is the same as in the above-described embodiment, and description thereof is omitted.

(Third embodiment)
In the embodiment described above, an example of referring to a table when specifying a correction value has been described. However, the embodiments described above are not limited to the method of referring to the table. In the third embodiment, a method of calculating a correction value using only a mathematical model is employed.

In the second embodiment, the speed correction value storage table is used. By applying it to the correction value Pv, the correction value can be calculated using only the mathematical model.

For example, in a general injection device, when the speed of the screw 330 is 0, the resistance value such as mechanical friction, in other words, the speed correction value is the largest. correction value) becomes smaller. When the speed of the screw 330 reaches a predetermined value, the relationship between speed and friction may be assumed to transition linearly, and the speed correction value may be changed linearly with respect to the speed. Since the variation is small, it may be treated as constant. A correction value can be calculated using only a mathematical model by applying such a change in speed correction value as a formula to formula (3).

As in the embodiment described above, the combination of the table and the mathematical model shall differ according to the implementation. For example, it is conceivable to use a table when it is judged that the time required for calculation is long, or to use a mathematical model when it is desired to reduce the storage capacity.

In the above-described embodiment, the method of specifying the correction value is explained in the state where the assembly of the screw 330 is not mounted, but the method of specifying the correction value is not limited. For example, when the screw 330 is mounted, the correction value may be specified by filling the cylinder 310 with resin and increasing the temperature, and then operating the screw 330 at a low speed. In this case, only the correction value based on the resistance at low speed can be identified. However, since the resistance value tends to decrease as the speed of the screw 330 increases, a correction value corresponding to the speed can be estimated.

(Modification)
The embodiment described above is an example in which the correction control unit 604 corrects the detection value output from the load detector 360 based on the combination of the circumferential position of the screw 330, the position of the screw 330, and the speed of the screw. explained. However, the embodiments described above are not limited to the method of specifying the correction value based on the combination of the circumferential position of the screw 330, the position of the screw 330, and the speed of the screw.

For example, the correction control section 604 may specify the correction value based on a combination of the circumferential position of the screw 330 and the position of the screw 330 . Furthermore, the correction control unit 604 identifies the specified pressure setting value based on the combination of the circumferential position of the screw 330 and the position of the screw 330, and the pressure control unit 606 operates according to the specified pressure setting value. Pressure control may be performed. The method of specifying the correction value or the pressure setting value based on the combination of the circumferential position of the screw 330 and the position of the screw 330 may use a table or a mathematical model.

As another example, the correction control unit 604 may specify the correction value based on a combination of the circumferential position of the screw 330 and the speed of the screw 330 . Furthermore, the correction control unit 604 identifies the specified pressure setpoint based on the combination of the circumferential position of the screw 330 and the speed of the screw 330, and the pressure control unit 606 operates according to the specified pressure setpoint. Pressure control may be performed.

As another example, the correction control section 604 may specify a correction value based on a combination of the axial position of the screw 330 and the speed of the screw 330 . Further, correction control 604 identifies the identified pressure set point based on a combination of the axial position of screw 330 and the speed of screw 330, and pressure control 606 operates according to the identified pressure set point. Pressure control may be performed.

In this way, even if the correction value or the pressure setting value is specified based on a combination of two elements of the circumferential position of the screw 330, the position of the screw 330, and the speed of the screw, the specified Since the detected value can be corrected with the corrected correction value and the pressure can be controlled with the corrected pressure setting value, it is possible to improve the detection accuracy and the accuracy of the pressure control.

Furthermore, the method is not limited to the method of specifying the correction value by combining two or more elements, and the correction value may be specified from one element. For example, the correction value and the pressure setting value may be specified based on the circumferential position of the screw 330 . Further, the correction value and the pressure setting value may be specified based on the axial position of the screw 330 . Also, based on the speed of the screw 330, the correction value and the pressure setting value may be specified.

In the above-described embodiment and modification, it is possible to improve the accuracy of pressure control in the injection/metering process, and reduce variations in detected force values due to resin pressure between shots. As a result, it is possible to improve the accuracy of the pressure control for filling the molding material and the detection of the force due to the resin pressure.

Although the embodiments of the injection molding machine according to the present invention have been described above, the present invention is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These also naturally belong to the technical scope of the present invention.

This application claims priority based on Japanese Patent Application No. 2021-061135 filed on March 31, 2021, and the entire contents of this Japanese Patent Application are incorporated herein by reference.

10... Injection molding machine 300... Injection device 330... Screw 340... Weighing motor 350... Injection motor 700... Control device 601... Correction information storage section 602... Acquisition section 603... Registration unit 604... Correction control unit 605... Display control unit 606... Pressure control unit

Claims

an injection device that fills the mold device with molding material;
a control device that controls the injection device;
The injection device has a cylinder for heating the molding material, a screw arranged in the cylinder, and a metering motor for rotating the screw,
The control device is
A pressure detector that corrects a pressure set value used for pressure control of the screw or detects the pressure acting on the screw based on the circumferential position of the screw that changes based on the operation of the metering motor. Having a correction control unit that corrects the detection value output from
Injection molding machine.
The control device is
further comprising a storage unit that stores correction information corresponding to the circumferential position of the screw;
The correction control unit corrects a pressure set value used for pressure control of the screw based on the correction information corresponding to the position in the circumferential direction, or a pressure detector that detects the pressure acting on the screw. Correct the output detection value,
The injection molding machine according to claim 1.
an injection device that fills the mold device with molding material;
a control device that controls the injection device;
The injection device has a cylinder for heating the molding material, a screw arranged in the cylinder, and an injection motor for moving the screw,
The control device is
A pressure detector that corrects a pressure set value used for pressure control of the screw or detects the pressure acting on the screw based on the axial position of the screw that changes based on the operation of the injection motor. Having a correction control unit that corrects the detection value output from
Injection molding machine.
The control device is
further comprising a storage unit that stores correction information corresponding to the axial position of the screw;
The correction control unit corrects a pressure set value used for pressure control of the screw based on the correction information corresponding to the axial position, or a pressure detector that detects the pressure acting on the screw. Correct the output detection value,
The injection molding machine according to claim 3.
an injection device that fills the mold device with molding material;
a control device that controls the injection device;
The injection device has a cylinder for heating the molding material, a screw arranged in the cylinder, and an injection motor for moving the screw,
The control device is
Based on the speed of the screw, which changes based on the operation of the injection motor, the pressure set value used for pressure control of the screw is corrected, or the pressure is output from a pressure detector that detects the pressure acting on the screw. having a correction control unit that corrects the detected value,
Injection molding machine.
The control device is
further comprising a storage unit that stores correction information corresponding to the speed of the screw;
The correction control unit corrects a pressure setting value used for pressure control of the screw based on the correction information corresponding to the speed of the screw, or outputs from a pressure detector that detects the pressure acting on the screw. to correct the detected value,
The injection molding machine according to claim 5.