CN116745046A - Injection molding machine - Google Patents

Abstract

The injection molding machine has: an injection device for filling the mold device with molding material; and a control device for controlling the injection device. The injection device has a cylinder that heats the molding material, a screw disposed in the cylinder, and a metering motor that rotates the screw. The control device has a correction control unit that corrects the pressure setting value used in the pressure control of the screw or corrects the action on the screw based on the circumferential position of the screw that changes with the operation of the metering motor. The detection value of the pressure output by the pressure detector.

Description

Injection molding machine

Technical field

The present invention relates to an injection molding machine.

Background technique

The injection molding machine includes a cylinder to which resin particles as a molding material are supplied, and a heater to heat the cylinder in order to melt the resin particles. Injection molding machines manufacture molded products by melting resin particles in a cylinder and filling the molten resin into the cavity space in the mold device.

Injection molding machines are equipped with various sensors. Furthermore, it is preferable to identify accurate torque and stress based on values detected by sensors.

existing technical documents

patent documents

Patent Document 1: Japanese Patent Application Publication No. 2009-045904

Contents of the invention

Invent the problem to be solved

In Patent Document 1, the allowable upper limit of the torque of the screw is set by measuring and storing the torque during measurement and inputting it into a preconceived function. Therefore, it is possible to realize the allowable upper limit of the screw torque without performing complicated calculation of the mechanical strength of the material. Torque monitoring of upper limit value.

On the other hand, in order to appropriately control and monitor an injection molding machine, it is desired to detect not only the torque but also the accurate resin pressure. However, eccentric loads caused by friction and posture changes of driving parts affect the detection values of the load detector.

One aspect of the present invention provides a technology that improves the accuracy of pressure control for filling molding materials and detection of pressure acting on a screw.

Means used to solve problems

An injection molding machine according to one aspect of the present invention includes 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 disposed in the cylinder, and a metering motor that rotates the screw. The control device has a correction control unit that corrects the pressure setting value used in the pressure control of the screw or corrects the action on the screw based on the circumferential position of the screw that changes with the operation of the metering motor. The detection value of the pressure output by the pressure detector.

An injection molding machine according to one aspect of the present invention includes 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 disposed in the cylinder, and an injection motor that moves the screw along the cylinder. The control device has a correction control unit that corrects the pressure setting value used in the pressure control of the screw based on the axial position of the screw that changes with the operation of the injection motor or corrects the pressure acting on the screw from detection. The detection value output by the pressure detector of the screw pressure.

An injection molding machine according to one aspect of the present invention includes 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 disposed in the cylinder, and an injection motor that moves the screw. The control device has a correction control unit that corrects a pressure setting value used for pressure control of the screw based on the speed of the screw that changes with the operation of the injection motor or corrects a pressure setting value obtained from detecting the pressure acting on the screw. The detection value output by the pressure detector.

Invention effect

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

Description of drawings

FIG. 1 is a diagram showing a state when mold opening of the injection molding machine according to one embodiment is completed.

FIG. 2 is a diagram showing a state of the injection molding machine during mold closing according to the embodiment.

FIG. 3 is a diagram showing a state of the injection device according to the embodiment when injection is started.

FIG. 4 is a diagram showing a state of the injection device according to the embodiment when injection is completed.

FIG. 5 is a partially enlarged view of the injection device according to the embodiment in a state when injection is completed.

FIG. 6 is a diagram showing the structural elements of the control device according to the embodiment in functional blocks.

FIG. 7 is a conceptual diagram showing the pressure detected by the load detector during measurement according to the first embodiment.

8 is a diagram illustrating the relationship between the detection value detected by the load detector according to the first embodiment and the force caused by the resin pressure.

9 is a diagram showing detection values detected by a 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.

FIG. 10 is a diagram illustrating a table of the correction information storage unit registered in the registration unit according to the first embodiment.

FIG. 11 is a diagram showing a flowchart for registering a correction value in a correction information storage unit in the control device according to the first embodiment.

FIG. 12 is a flowchart of display processing during measurement in the control device according to the first embodiment.

13 is a diagram illustrating resistance (including friction) that changes depending on the circumferential position of the screw (rotation angle) or the position of the screw (phase of the injection spline shaft).

FIG. 14 is a diagram showing the structure of a speed correction value storage table stored in a correction information storage unit according to the second embodiment.

FIG. 15 is a diagram illustrating changes in correction values calculated by the correction control unit using equation (3) according to the second embodiment.

Detailed ways

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

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

As shown in FIGS. 1 and 2 , the injection molding machine 10 includes a mold clamping device 100 and a mold opening and closing device 800 , an ejection device 200 for ejecting a molded product formed by the mold device 800 , and an injection device 300 for opening and closing the mold device 800 . Injection molding material; moving device 400 to move the injection device 300 forward and backward relative to the mold device 800; control device 700 to control each component of the injection molding machine 10; and frame 900 to support each component of the injection molding machine 10. 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 respectively installed on the base plate 2 via horizontal adjustment casters 930 . The control device 700 is arranged in the internal 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 closing the mold (for example, the positive direction of the X-axis) is assumed to be forward, and the moving direction of the movable platen 120 when opening the mold (for example, the negative direction of the X-axis ) is set to the rear for explanation.

The mold clamping device 100 performs mold closing, pressure increasing, mold closing, pressure release, and mold opening of the mold device 800 . The mold device 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 and closing direction is a horizontal direction. The mold clamping device 100 includes a fixed platen 110 to which the fixed mold 810 is mounted, a movable platen 120 to which the movable mold 820 is mounted, and a moving mechanism 102 that moves the movable platen 120 relative to the fixed platen 110 in the mold opening and closing direction.

The fixed pressing plate 110 is fixed relative to the mold clamping device frame 910 . The fixed mold 810 is attached to the surface of the fixed platen 110 that faces the movable platen 120 .

The movable platen 120 is disposed to be movable relative to the mold clamping device frame 910 in the mold opening and closing direction. The guide 101 for guiding the movable platen 120 is laid on the mold clamping device frame 910 . The movable mold 820 is installed on the surface of the movable platen 120 that faces the fixed platen 110 .

The moving mechanism 102 moves the movable platen 120 forward and backward relative 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 has a toggle base 130 arranged at a distance from the fixed pressure plate 110, a connecting rod 140 connecting the fixed pressure plate 110 and the toggle base 130, and a mechanism for moving the movable pressure plate 120 in the mold opening and closing direction relative to the toggle base 130. The toggle mechanism 150, the mold clamping motor 160 that operates the toggle mechanism 150, the motion conversion mechanism 170 that converts the rotational motion of the mold clamping motor 160 into linear motion, and the mold thickness that adjusts the distance between the fixed pressure plate 110 and the toggle seat 130 Adjustment mechanism 180.

The toggle base 130 is spaced apart from the fixed pressure plate 110 and is mounted on the mold clamping device frame 910 so as to be movable in the mold opening and closing direction. In addition, the toggle seat 130 may be disposed to be movable along a guide laid on the mold clamping device frame 910 . The guide member of the toggle seat 130 may be the same as the guide member 101 of the movable pressure plate 120 .

In addition, in the present embodiment, the fixed platen 110 is fixed to the mold clamping device frame 910 and the toggle base 130 is disposed to be movable in the mold opening and closing direction relative to the mold clamping device frame 910. However, the toggle base 130 may be opposed to the mold closing device frame 910. The fixed platen 110 is fixed to the mold clamping device frame 910 and is disposed to be movable relative to the mold clamping device frame 910 in the mold opening and closing direction.

The connecting rod 140 connects the fixed pressure plate 110 and the toggle seat 130 with an interval L in the mold opening and closing direction. Multiple connecting rods 140 (for example, four connecting rods) may be used. The plurality of connecting rods 140 are arranged parallel to the mold opening and closing direction and extend according to the mold clamping force. A connecting rod strain detector 141 for detecting the strain of the connecting rod 140 may be provided on at least one connecting rod 140 . The connecting rod strain detector 141 sends a signal indicating the detection result to the control device 700 . The detection results of the connecting rod strain detector 141 are used for detection of mold clamping force and the like.

In addition, in this embodiment, the tie rod strain detector 141 is used as the 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, and may also be a piezoelectric type, a capacitive type, a hydraulic type, an electromagnetic type, etc., and its installation position is not limited to the connecting rod 140.

The toggle mechanism 150 is arranged between the movable pressure plate 120 and the toggle seat 130, and moves the movable pressure plate 120 relative to the toggle seat 130 in the mold opening and closing direction. The toggle mechanism 150 has a crosshead 151 that moves in the mold opening and closing direction, and a pair of link groups that bend and extend by the movement of the crosshead 151 . The pair of link groups each include a first link 152 and a second link 153 that are connected by pins or the like to be flexible and extendable. The first link 152 is swingably attached to the movable pressure plate 120 through a pin or the like. The second link 153 is swingably attached to the toggle seat 130 through a pin or the like. The second link 153 is attached to the crosshead 151 via the third link 154 . When the cross head 151 moves forward and backward relative to the toggle seat 130 , the first link 152 and the second link 153 bend and extend, so that the movable pressure plate 120 moves forward and backward relative to the toggle seat 130 .

In addition, the structure of the toggle mechanism 150 is not limited to the structure shown in FIGS. 1 and 2 . For example, in FIGS. 1 and 2 , the number of nodes of each link group is 5, but it may be 4, or one end of the third link 154 may be coupled to the first link 152 and the second link. Node of rod 153.

The mold clamping motor 160 is installed on the toggle seat 130 and operates the toggle mechanism 150 . The mold clamping motor 160 moves the cross head 151 forward and backward relative to the toggle seat 130 to flex and extend the first link 152 and the second link 153 to move the movable pressure plate 120 forward and backward relative to the toggle seat 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, a pulley, or the like.

The motion conversion mechanism 170 converts the rotational motion of the mold clamping motor 160 into the linear motion of the crosshead 151 . The motion conversion mechanism 170 includes a screw shaft and a screw nut screwed with the screw shaft. Balls or rollers can be interposed between the screw shaft and the screw nut.

The mold clamping device 100 performs a mold closing process, a pressure increasing process, a mold closing process, a depressurizing process, a mold opening process, etc., under the control of the control device 700 .

In the mold closing process, the mold closing motor 160 is driven to advance the crosshead 151 to the mold closing end position at a set moving speed, and the movable platen 120 is advanced to bring the movable mold 820 into contact with the fixed mold 810 . For example, the mold clamping motor encoder 161 or the like is used to detect the position and movement speed of the crosshead 151 . The mold clamping motor encoder 161 detects the rotation of the mold clamping motor 160 and sends a signal indicating the detection result to the control device 700 .

In addition, the crosshead position detector that detects the position of the crosshead 151 and the crosshead moving speed detector that detects the moving speed of the crosshead 151 are not limited to the mold clamping motor encoder 161, and conventional detectors can be used. Furthermore, the movable platen position detector that detects the position of the movable platen 120 and the movable platen moving speed detector that detects the moving speed of the movable platen 120 are not limited to the mold clamping motor encoder 161, and conventional detectors can be used. .

In the voltage boosting step, the mold clamping motor 160 is further driven to further advance the crosshead 151 from the mold closing end position to the mold closing position, thereby generating a mold clamping force.

In the mold closing process, the mold closing motor 160 is driven to maintain the position of the crosshead 151 at the mold closing position. In the mold clamping process, the mold clamping force generated in the pressure boosting process is maintained. In the mold closing process, a cavity space 801 (refer to 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 liquid molding material. The filled molding material is solidified, thereby obtaining a molded article.

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

In the depressurization process, the mold closing motor 160 is driven to retract the crosshead 151 from the mold closing position to the mold opening start position, and the movable platen 120 is retracted to reduce the mold closing force. The mold opening start position and the mold closing end position may be the same position.

In the mold opening process, the mold closing motor 160 is driven to cause the crosshead 151 to retreat from the mold opening start position to the mold opening end position at a set moving speed, so that the movable platen 120 retreats, so that the movable mold 820 is separated from the fixed mold 810 . Then, the ejection device 200 ejects the molded product from the movable mold 820 .

The setting conditions in the mold closing process, the pressure increasing process, and the mold clamping process are set collectively as a series of setting conditions. For example, the moving speed and position (including the mold closing start position, the moving speed switching position, the mold closing end position and the mold clamping position) and the mold clamping force of the crosshead 151 in the mold closing process and the pressure boosting process are set as a series of settings Conditions are set uniformly. The mold closing start position, the movement speed switching position, the mold closing end position, and the mold clamping position are arranged in order from the rear side to the front, and indicate the starting point and end point of the section where the movement speed is set. Set the movement speed for each section. The moving speed switching position can be one or multiple. You can switch positions without setting the movement speed. Only either the mold clamping position or the mold clamping force can be set.

The setting conditions in the depressurization process and the mold opening process are also set in the same manner. For example, the moving speed and position (mold opening start position, moving speed switching position, and mold opening end position) of the crosshead 151 in the depressurization process and the mold opening process are collectively set as a series of setting conditions. The mold opening start position, the moving speed switching position, and the mold opening end position are arranged in order from the front side to the rear, and represent the starting point and end point of the section where the moving speed is set. Set the movement speed for each section. The moving speed switching position can be one or multiple. You can switch positions without setting the movement speed. The mold opening start position and the mold closing end position may be the same position. Furthermore, the mold opening end position and the mold closing start position may be the same position.

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

However, the toggle mechanism 150 amplifies the driving force of the mold clamping motor 160 and transmits it to the movable platen 120 . Its magnification is also called toggle magnification. The toggle magnification changes according to the angle θ formed by the first link 152 and the second link 153 (hereinafter also referred to as “link angle θ”). The link angle θ is found 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, temperature change of the mold device 800, etc., the mold thickness is adjusted to obtain a predetermined mold clamping force when the mold is closed. In the mold thickness adjustment, for example, the distance L between the fixed platen 110 and the toggle seat 130 is adjusted so that the link angle θ of the toggle mechanism 150 becomes a predetermined angle when the movable mold 820 contacts the fixed mold 810 .

The mold clamping device 100 has a mold thickness adjustment mechanism 180 . The mold thickness adjustment mechanism 180 adjusts the distance L between the fixed pressure plate 110 and the toggle seat 130 to adjust the mold thickness. In addition, the timing of the mold thickness adjustment is performed, for example, from the end of the molding cycle to the start of the next molding cycle. The mold thickness adjustment mechanism 180 has, for example, a screw shaft 181 formed at the rear end of the connecting rod 140; a screw nut 182 that is rotatable and non-advanced on the toggle seat 130; and a mold thickness adjustment motor 183 that allows the The screw nut 182 screwed onto the screw shaft 181 rotates.

A screw shaft 181 and a screw nut 182 are provided for each connecting rod 140 . The rotational driving force of the mold thickness adjustment motor 183 can be transmitted to the plurality of screw nuts 182 via the rotational driving force transmission part 185 . A plurality of screw nuts 182 can be rotated synchronously. In addition, by changing the transmission path of the rotational driving force transmission part 185, the plurality of screw nuts 182 can be rotated individually.

The rotational driving force transmission part 185 is composed of, for example, a gear or the like. At this time, a driven gear is formed on the outer periphery of each screw nut 182, a driving gear is installed on the output shaft of the mold thickness adjustment motor 183, and an intermediate gear meshing with the plurality of driven gears and driving gears is located in the center of the toggle seat 130 Keep it spinning freely. In addition, the rotational driving force transmission part 185 may be comprised by a belt, a pulley, etc., instead of a gear.

The action of the mold thickness adjustment mechanism 180 is controlled by the control device 700 . The control device 700 drives the mold thickness adjustment motor 183 to rotate the screw nut 182 . As a result, the position of the toggle seat 130 relative to the connecting rod 140 is adjusted, and the distance L between the fixed pressure plate 110 and the toggle seat 130 is adjusted. In addition, multiple mold thickness adjustment mechanisms can also be used in combination.

The gap L is detected using the mold thickness adjustment motor encoder 184. The mold thickness adjustment motor encoder 184 detects the rotation amount and rotation direction of the mold thickness adjustment 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 to monitor and control the position of the toggle seat 130 and the interval L. In addition, the toggle base position detector that detects the position of the toggle base 130 and the interval detector that detects the interval L are not limited to the mold thickness adjustment motor encoder 184, and conventional detectors can be used.

The mold clamping device 100 may have a mold temperature regulator that adjusts the temperature of the mold device 800 . The mold device 800 has a flow path for the temperature adjustment medium inside the mold device 800 . The mold temperature regulator adjusts the temperature of the temperature-adjusting medium supplied to the flow path of the mold device 800, thereby adjusting the temperature of the mold device 800.

In addition, the mold clamping device 100 of this embodiment is a horizontal type in which the mold opening and closing direction is a horizontal direction, but may be a vertical type in which the mold opening and closing direction is an up-down direction.

In addition, the mold clamping device 100 of this embodiment includes the mold clamping motor 160 as a drive source, but may include a hydraulic cylinder instead of the mold clamping motor 160 . Furthermore, the mold clamping device 100 may include a linear motor for mold opening and closing, and may also include an electromagnet for mold clamping.

(ejector device)

In the description of the ejector device 200 , similarly to the description of the mold clamping device 100 and the like, the moving direction of the movable platen 120 when closing the mold (for example, the positive direction of the The moving direction of the pressure plate 120 (for example, the negative direction of the X-axis) will be explained assuming that it is backward.

The ejection device 200 is installed on the movable pressure plate 120 and moves forward and backward together with the movable pressure plate 120 . The ejection device 200 includes an ejection rod 210 for ejecting the molded product from the mold device 800 and a drive mechanism 220 for moving the ejection rod 210 in the moving direction (X-axis direction) of the movable platen 120 .

The ejector rod 210 is arranged to move forward and backward freely in the through hole of the movable pressure plate 120 . The front end of the ejector rod 210 is in contact with the ejector plate 826 of the movable mold 820 . The front end of the ejector rod 210 may or may not be connected to the ejector plate 826 .

The drive mechanism 220 has, for example, an ejection motor and a motion conversion mechanism that converts the rotational motion of the ejection motor into the linear motion of the ejection rod 210 . The motion conversion mechanism includes a screw shaft and a screw nut screwed to the screw shaft. Balls or rollers can be interposed between the screw shaft and the screw nut.

The ejection device 200 performs the ejection process under the control of the control device 700 . In the ejection process, the ejection rod 210 is advanced from the standby position to the ejection position at a set movement speed, thereby advancing the ejection plate 826 to eject the molded product. Then, the ejection motor is driven to retract the ejection rod 210 at the set moving speed, and the ejection plate 826 is retracted to the original standby position.

For example, an ejector motor encoder is used to detect the position and moving speed of the ejector rod 210 . The ejection motor encoder detects the rotation of the ejection motor and sends a signal indicating the detection result to the control device 700 . In addition, the ejector rod position detector that detects the position of the ejector rod 210 and the ejector rod moving speed detector that detects the moving speed of the ejector rod 210 are not limited to the ejector motor encoder, and conventional detectors 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 in the direction in which the screw 330 is movable) is assumed to be The description will be made assuming that the axial direction of the screw 330 during measurement (for example, the positive direction of the X-axis in the direction in which the screw 330 is movable) is referred to as the front.

The injection device 300 is provided on a sliding base 301 , and the sliding base 301 is arranged to move forward and backward relative to the injection device frame 920 . The injection device 300 is arranged to move forward and backward relative to the mold device 800 . The injection device 300 is in contact with the mold device 800 and fills the cavity space 801 in the mold device 800 with molding material. The injection device 300 includes, for example, a cylinder 310 that heats the molding material, a nozzle 320 provided at the front end of the cylinder 310 , a screw 330 that is freely rotatable and forward-retractable in the cylinder 310 , and a metering motor that rotates the screw 330 . 340. The injection motor 350 that moves the screw 330 forward and backward, and the load detector 360 that detects the load transmitted between the injection motor 350 and the screw 330 .

The cylinder 310 heats the molding material supplied into the cylinder 310 from the supply port 311 . Molding materials include, for example, resin. The molding material is formed in a granular form, for example, and is supplied to the supply port 311 in a solid state. The 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 periphery of the rear portion of the cylinder 310 . A heater 313 such as a tape heater and a temperature detector 314 are provided on the outer periphery of the cylinder 310 in front of the cooler 312 .

The cylinder 310 is divided into a plurality of regions along the axial direction of the cylinder 310 (for example, the X-axis direction). Heaters 313 and temperature detectors 314 are respectively provided in a plurality of areas. Set temperatures are set for each of the plurality of areas, and the control device 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 presses the mold device 800 . A heater 313 and a temperature detector 314 are provided on the outer periphery of the nozzle 320 . The control device 700 controls the heater 313 so that the detected temperature of the nozzle 320 becomes the set temperature.

The screw 330 is disposed to be freely rotatable and move forward and backward in the cylinder 310 . When the screw 330 is rotated, the molding material is conveyed forward along the spiral groove of the screw 330 . The molding material is gradually melted by the heat from the cylinder 310 while being transported forward. As the liquid molding material is transported to the front of the screw 330 and accumulated in the front of the cylinder 310 , the screw 330 is moved backward. Then, 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 .

The check ring 331 is attached to the front of the screw 330 so as to be able to move forward and retreat freely. The check ring 331 serves as a check valve to prevent the molding material from flowing back from the front to the rear of the screw 330 when the screw 330 is pushed forward.

When the screw 330 is advanced, the check ring 331 is pushed backward by the pressure of the molding material in front of the screw 330 and retreats relative to the screw 330 to a closed position where the flow path of the molding material is blocked (see FIG. 2 ). This prevents the molding material accumulated in front of the screw 330 from flowing backward.

On the other hand, when the screw 330 is rotated, the check ring 331 is pushed forward by the pressure of the molding material transported forward along the spiral groove of the screw 330, and advances relative to the screw 330 to open the molding material. The open position of the flow path (refer to Figure 1). Thereby, the molding material is conveyed to the front of the screw 330 .

The check ring 331 may be of a co-type that rotates together with the screw 330 or a non-co-type that does not rotate together with the screw 330 .

In addition, the injection device 300 may have a driving source that moves the check ring 331 forward and backward between the open position and the closed position relative to the screw 330 .

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

The injection motor 350 moves the screw 330 forward and backward. A motion conversion mechanism that converts the rotational motion of the injection motor 350 into the linear motion of the screw 330 is provided between the injection motor 350 and the screw 330 . The motion conversion mechanism includes, for example, a screw shaft and a screw nut screwed to the screw shaft. Balls, rollers, etc. can be installed between the screw shaft and the screw nut. The driving source for advancing and retracting the screw 330 is not limited to the injection motor 350, and may be a hydraulic cylinder, for example.

The load detector 360 detects the load transferred 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 the 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 signal of the detected load 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, and is used for the pressure the screw 330 bears from the molding material, the back pressure on the screw 330 and the pressure acting from the screw 330 on the molding material. Control and monitoring of pressure, etc.

In addition, the pressure detector that detects the pressure of the molding material is not limited to the load detector 360, and a conventional detector can be used. For example, a nozzle pressure sensor or an in-mold pressure sensor can be used. The nozzle pressure sensor is provided on the nozzle 320 . The mold internal pressure sensor is provided inside the mold device 800 .

The injection device 300 performs a measuring process, a filling process, a pressure maintaining process, etc. under the control of the control device 700. The filling process and the pressure maintaining process can be collectively referred to as the injection process.

In the metering process, the metering motor 340 is driven to rotate the screw 330 at a set rotation speed, and the molding material is transported forward along the spiral groove of the screw 330 . Thereby, the molding material is gradually melted. As the liquid molding material is transported to the front of the screw 330 and accumulated in the front of the cylinder 310 , the screw 330 is moved backward. For example, the metering motor encoder 341 is used to detect the rotation speed of the screw 330 . The metering motor encoder 341 detects the rotation of the metering motor 340 and sends a signal indicating the detection result to the control device 700 . In addition, the screw rotation speed detector that detects the rotation speed of the screw 330 is not limited to the metering motor encoder 341, and a conventional detector can be used.

In the metering process, in order to limit the rapid retreat of the screw 330, the injection motor 350 can be driven to apply a set back pressure to the screw 330. For example, a load detector 360 is used to detect the back pressure on the screw 330 . When the screw 330 is retracted to the measurement end position and a predetermined amount of molding material is accumulated in front of the screw 330, the measurement process is completed.

The axial position and rotation speed of the screw 330 in the measurement process are set collectively as a series of setting conditions. For example, set the measurement start position, rotation speed switching position and measurement end position. These positions are arranged in order from the front side to the rear, and indicate the starting point and end point of the section where the rotation speed is set. Set the rotation speed for each section. The speed switching position can be one or multiple. It is not necessary to set the speed switching position. Furthermore, 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 moving 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 . For example, the injection motor encoder 351 is used to detect the position and movement speed of the screw 330 . The injection motor encoder 351 detects the 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 pressure maintaining process (so-called V/P switching) is performed. The position where V/P switching is performed is also called a V/P switching position. The set moving speed of the screw 330 can 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 set collectively as a series of setting conditions. For example, the filling start position (also called "injection start position"), the movement speed switching position, and the V/P switching position are set. These positions are arranged in order from the rear side to the front, and indicate the starting point and end point of the section where the movement speed is set. Set the movement speed for each section. The moving speed switching position can be one or multiple. You can switch positions without setting the movement speed.

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 the screw 330 is detected by the load detector 360 . When the pressure of the screw 330 is below the set pressure, the screw 330 moves forward at the set moving speed. On the other hand, when the pressure of the screw 330 exceeds the set pressure, in order to protect the mold, the screw 330 moves forward at a slower moving speed than the set moving speed so that the pressure of the screw 330 becomes less than the set pressure.

In addition, during the filling process, after the position of the screw 330 reaches the V/P switching position, the screw 330 can be paused at the V/P switching position, and then the V/P switching is performed. Just before V/P switching is performed, instead of stopping the screw 330 , the screw 330 may be moved forward or backward at a slight speed. Furthermore, the screw position detector that detects the position of the screw 330 and the screw moving speed detector that detects the moving speed of the screw 330 are not limited to the injection motor encoder 351, and conventional detectors can be used.

In the pressure holding 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 a set pressure, and the cylinder is The remaining molding material within the body 310 is pushed toward the mold device 800 . A shortage of molding material due to cooling shrinkage in the mold device 800 can be replenished. For example, the load detector 360 is used to detect the holding pressure. The setting value of the holding pressure can be changed based on the elapsed time since the start of the pressure holding process, etc. The holding pressure and the holding time for holding the holding pressure in multiple holding steps can be set separately, or they can be set collectively as a series of setting conditions.

During the pressure maintaining process, the molding material in the cavity space 801 in the mold device 800 is gradually cooled. At the end of the pressure maintaining process, the entrance of the mold cavity space 801 is blocked by the solidified molding material. This state is called gate sealing and prevents backflow of molding material from the cavity space 801 . After the pressure holding process, the cooling process begins. In the cooling process, the molding material in the cavity space 801 is solidified. In order to shorten the molding cycle time, the metering process can be performed in the cooling process.

In addition, the injection device 300 of this embodiment is a coaxial screw type, but it may also be a pre-molding type or the like. The pre-molding type injection device supplies the molding material melted in the plasticizing cylinder to the injection cylinder, and injects the molding material from the injection cylinder into the mold device. In the plasticizing cylinder, the screw is configured to rotate freely and cannot advance or retreat, or the screw is configured to rotate freely and advance or retreat freely. On the other hand, in the injection cylinder, the plunger is arranged to move forward and backward freely.

In addition, the injection device 300 of this embodiment is a horizontal type in which the axial direction of the cylinder 310 is a horizontal direction, but may be a vertical type in which the axial direction of the cylinder 310 is an up-down direction. The mold clamping device combined with the vertical injection device 300 may be vertical or horizontal. Similarly, the mold clamping device combined with the horizontal injection device 300 may be horizontal or vertical.

(mobile device)

In the description of the moving device 400, similarly to the description of the injection device 300, the axial direction of the screw 330 during filling (for example, the negative direction of the forward direction) as the rear direction.

The moving device 400 moves the injection device 300 forward and backward relative to the mold device 800 . Furthermore, the moving device 400 presses the nozzle 320 with respect to the mold device 800 to generate a nozzle contact pressure. The moving device 400 includes a hydraulic pump 410, a motor 420 as a driving 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. The hydraulic pump 410 is a bidirectionally rotatable pump. By switching the rotation direction of the motor 420, the hydraulic pump 410 sucks a working fluid (for example, oil) from one of the first port 411 and the second port 412 and discharges it from the other port to generate hydraulic pressure. In addition, the hydraulic pump 410 can suck the working fluid from the tank and discharge the working fluid from either the first port 411 or the second port 412 .

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

The hydraulic cylinder 430 has a cylinder body 431, a piston 432, and a piston rod 433. The cylinder body 431 is fixed relative to the injection device 300 . The piston 432 divides 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. The piston rod 433 is fixed relative to the fixed pressure plate 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 working 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 advances and the nozzle 320 is pressed against the fixed mold 810 . The front chamber 435 functions as a pressure chamber in which the nozzle contact pressure of the nozzle 320 is generated by the pressure of the operating 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 operating 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 retreats and the nozzle 320 separates from the fixed mold 810 .

In addition, in this embodiment, the moving device 400 includes the hydraulic cylinder 430, but the present invention is not limited thereto. For example, instead of the hydraulic cylinder 430, an electric motor and a motion conversion mechanism that converts the rotational motion of the electric motor into 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. 1 and 2 . The control device 700 causes the CPU 701 to execute a program stored in the storage medium 702 to perform various controls. Furthermore, the control device 700 receives signals from the outside through the input interface 703 and sends signals to the outside through the output interface 704 .

The control device 700 repeatedly performs the measuring process, the mold closing process, the pressure increasing process, the mold clamping process, the filling process, the pressure holding process, the cooling process, the depressurizing process, the mold opening process, the ejection process, etc., to repeatedly manufacture molded products. A series of operations for obtaining a molded product, for example, the operations from the start of the measuring process to the start of the next measuring process are also called "injection" or "molding cycle". In addition, the time required for one injection is also called "molding cycle time" or "cycle time."

A molding cycle includes, for example, a measuring process, a mold closing process, a pressurizing process, a mold closing process, a filling process, a pressure holding process, a cooling process, a depressurizing process, a mold opening process, and an ejection process in order. The order here is the order in which each process starts. The filling process, pressure holding process and cooling process are carried out during the mold closing process. The start of the mold clamping process may be coincident with the start of the filling process. The end of the depressurization process coincides with the start of the mold opening process.

In addition, in order to shorten the molding cycle time, multiple processes can be performed simultaneously. For example, the metering process can be performed during the cooling process of the previous molding cycle or during the mold closing process. In this case, the mold closing process can be performed at the beginning of the molding cycle. Also, the filling process may be started in the mold closing process. Furthermore, the ejection process can be started during the mold opening process. When an opening and closing valve that opens and closes the flow path of the nozzle 320 is provided, the mold opening process can be started in the metering process. Even if the mold opening process is started during the metering process, as long as the on-off valve closes the flow path of the nozzle 320 , the molding material will not leak from the nozzle 320 .

In addition, the one-time molding cycle may have processes other than the measuring process, the mold closing process, the pressure increasing process, the mold clamping process, the filling process, the pressure holding process, the cooling process, the depressurizing process, the mold opening process, and the ejection process.

For example, after the pressure maintaining process is completed and before the measurement process is started, a pre-measurement suction process of retracting the screw 330 to a preset measurement start position may be performed. The pressure of the molding material accumulated in front of the screw 330 can be reduced before the measurement process is started, and the screw 330 can be prevented from suddenly retreating when the measurement process is started.

Furthermore, after the measurement process is completed and before the filling process is started, a post-measurement suction process of retracting the screw 330 to a preset filling start position (also referred to as an "injection start position") may be performed. The pressure of the molding material accumulated in front of the screw 330 can be reduced before the filling process is started, and leakage of the molding material from the nozzle 320 before the filling process is started can be prevented.

The control device 700 is connected to an operating device 750 that accepts user input operations and a display device 760 that displays a screen. The operation device 750 and the display device 760 are composed of, for example, the touch panel 770 and may be integrated. The touch panel 770 as the display device 760 displays a screen under the control of the control device 700 . For example, information such as settings of the injection molding machine 10 and the current status of the injection molding machine 10 can be displayed on the screen of the touch panel 770 . In addition, operation units such as buttons and input fields for accepting user input operations may be displayed on the screen of touch panel 770 . The touch panel 770 as the operating device 750 detects the user's input operation on the screen and outputs a signal corresponding to the input operation to the control device 700 . Thereby, for example, the user can operate the operation unit provided on the screen while confirming the information displayed on the screen, and perform settings (including input of setting values) of the injection molding machine 10 and the like. Furthermore, the user can operate the injection molding machine 10 corresponding to the operation unit by operating the operation unit provided on the screen. In addition, the operation of the injection molding machine 10 may be, for example, the operation (including stopping) of the mold clamping device 100, the ejection device 200, the injection device 300, the moving device 400, and the like. In addition, the operation of the injection molding machine 10 may be switching of the screen displayed on the touch panel 770 as the display device 760, or the like.

In addition, although the operation device 750 and the display device 760 of this embodiment are integrated into the touch panel 770, they may be provided independently. Furthermore, multiple 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 fixed platen 110).

(Details of injection device)

FIG. 3 is a diagram showing a state of the injection device according to the embodiment when injection is started.

FIG. 4 is a diagram showing a state of the injection device according to the embodiment when injection is completed. FIG. 5 is a partial enlarged view of FIG. 4 . 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 advances and retreats while the injection motor 350 rotates, and a bearing frame 370 that rotatably supports the drive shaft 362 via the bearing 361.

The support frame 304 is provided on the sliding base 301. The sliding base 301 moves forward and backward along two guides 302 (only one is shown in FIGS. 3 and 4 ). Two guides 302 are laid on the injection device frame 920. The two guides 302 respectively extend in the X-axis direction. The two guides 302 are arranged at intervals in the Y-axis direction. The support frame 304 is provided on the sliding base 301 so as to be rotatable about a vertical rotation axis 304Z. The injection device main body 303 can be rotated together with the support frame 304.

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

The support frame 304 has a front flange 307, a rear flange 308 and a plurality of connecting rods 309. The front flange 307 is installed on the front rotating plate 305. The rear flange 308 is installed on the rear rotating plate 306. The connecting rod 309 connects the front flange 307 and the rear flange 308 with a gap therebetween.

The cylinder 310 and the metering motor 340 are installed on the front flange 307. The cylinder 310 is arranged in front of the front flange 307 and is mounted to the front flange 307 via the cylinder 315 . The metering motor 340 is disposed behind the front flange 307 and in front of the rear flange 308 .

On the other hand, the injection motor 350 is installed on the rear flange 308 . The injection motor 350 is disposed behind the rear flange 308 and is attached to the rear flange 308 via a load detector 360 described below.

Metering motor 340 rotates 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 a bearing 349 that rotatably supports the rotor 343. The stator 342 includes a front flange 342a that holds the bearing 349, a rear flange 342b that holds the bearing 349, and a housing 342c that connects the front flange 342a and the rear flange 342b. The rotational motion of the metering motor 340 is transmitted to the bearing frame 370 , and then transmitted from the bearing frame 370 to the screw 330 .

The bearing frame 370 has a screw mounting portion 372 for mounting the screw 330 and a metering spline shaft 371 spline-connected to the rotor 343 of the metering motor 340 . The metering spline shaft 371 is arranged inside the rotor 343 of the metering motor 340 . A metering spline nut 344 is provided in 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 is spline-connected to the metering spline nut 344. In addition, 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 has a stator 352 fixed to the rear flange 308 via a load detector 360, a rotor 353 rotating inside the stator 352, and a bearing 359 that rotatably supports the rotor 353. The rotational motion of the injection motor 350 is converted into the rotational linear motion of the drive shaft 362, and then converted into the linear motion of the bearing frame 370. As the bearing frame 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 rotation shaft 365 in order on the same straight line from the rear side to the front.

The injection spline shaft 363 is arranged inside the rotor 353 of the injection motor 350 . An injection spline nut 354 is provided in the rotor 353 . 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 is splined to the injection spline nut 354 . In addition, the number of key grooves and the number of keys may be one.

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

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

By advancing and retreating while the rotating shaft 365 rotates, the bearing frame 370 advances and retreats, and the screw 330 advances and retreats. When the screw 330 advances or retreats, the metering motor 340 does not advance or retreat. This is because the metering spline nut 344 of the metering motor 340 is splined to the metering spline shaft 371 of the bearing frame 370 . Since the metering motor 340 is not included in the driving objects of the injection motor 350, the inertia of the driving objects of the injection motor 350 is small, and the acceleration when the screw 330 starts to advance is fast.

In addition, the structure of the injection device 300 is not limited to the structure shown in FIG. 3 and FIG. 4 . For example, the arrangement of the driving source of the driving screw 330 (for example, the metering motor 340 and the injection motor 350) is not limited to the arrangement shown in FIGS. 3 and 4 . 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 may not be arranged on the same straight line.

Furthermore, the structure of the transmission mechanism that transmits the driving force of the driving source to the screw 330 is not limited to the structure shown in FIGS. 3 and 4 . The structure of the transmission mechanism is appropriately changed according to the arrangement of the driving source of the driving screw 330 . For example, when the rotation center lines of the metering motor 340 and the rotation center line of the screw 330 which are parallel to each other are staggered in a direction orthogonal to these rotation center lines, a timing belt may be used. Similarly, when the rotation center lines of the injection motor 350 and the rotation center line of the screw 330, which are parallel to each other, are staggered in a direction orthogonal to these rotation center lines, a timing belt can be used.

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

The flange 377 is fastened to the spline nut 376 via the first bolt 378 . The spline nut 376 is fastened to the bearing frame 370 via the second bolt 379 and presses the load detector 360 from the front. The operation of loosening or tightening the first bolt 378 and the second bolt 379 is performed from the window 316 of the cylinder 315 arranged between the front flange 307 and the cooler 312 .

The cylindrical body 315 includes a cylindrical portion 315a protruding forward from the front flange 307 and an inner flange portion 315b protruding from the front end surface of the cylindrical portion 315a inwardly of the cylindrical 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 in which the annular gasket 381 is fitted and an annular groove in which the sliding ring 382 is fitted are formed on the outer peripheral surface of the bearing frame 370 .

The annular gasket 381 is held by, for example, the bearing frame 370 , is in sliding contact with the rotor 343 of the metering motor 340 , and seals the gap between the rotor 343 and the bearing frame 370 . This can prevent the lubricant supplied to the metering spline shaft 371 from leaking to the screw 330 side.

The annular gasket 381 only needs to be installed at a position further forward than the key 371a of the metering spline shaft 371. It can be installed on the metering spline shaft 371 or on the screw mounting portion 372 shown in Figures 3 to 5.

As the annular gasket 381, for example, an O-ring with a circular cross-section is used, and the gasket is compressed appropriately. The annular gasket 381 is made of a softer material than the sliding ring 382 in order to ensure sealing performance. Examples of the material of the annular gasket 381 include rubber such as butyl rubber.

In addition, in the present embodiment, the annular gasket 381 is held by the bearing frame 370, but it may be held by the rotor 343 of the metering motor 340, be in sliding contact with the bearing frame 370, and seal the connection between the rotor 343 and the screw mounting part 372. gap.

The sliding ring 382 is held by, for example, the screw mounting portion 372 and is in sliding contact with the rotor 343 of the metering motor 340 so that the center line of the rotor 343 is aligned with the center line of the screw mounting portion 372 . This can prevent the rotor 343 from engaging with the screw mounting portion 372 . Furthermore, the application of eccentric load to the annular gasket 381 can be suppressed.

The sliding ring 382 suppresses eccentricity between the rotor 343 and the screw mounting portion 372 and is made of a material harder than the annular gasket 381 . As a material of the sliding ring 382, a crystalline resin with high self-lubricating properties or the like is used. Examples of crystalline resins include polytetrafluoroethylene (PTFE), polyamide (PA), polyester (PEs), polyethylene (PE), and the like. The greater the degree of crystallinity, the greater the self-lubricity. The sliding ring 382 may be formed of resin other than crystalline resin, for example, phenol cloth resin.

Unlike the annular gasket 381, the sliding ring 382 does not ensure sealing performance, and therefore has a crack in a part of the circumferential direction. This crack is formed for the installation and removal of the sliding ring 382, expands during the installation and removal, and then returns to its original state due to the elastic restoring force of the sliding ring 382.

In addition, in the present embodiment, the sliding ring 382 is held by the screw mounting part 372, but it may be held by the rotor 343 of the metering motor 340 and be in sliding contact with the screw mounting part 372 so that the center line of the rotor 343 is in contact with the screw mounting part 372. 372 centerline alignment. Furthermore, the number of sliding rings 382 may be multiple.

As shown in FIGS. 3 to 5 , a sliding ring 382 and an annular gasket 381 are arranged in order from the key 371 a side (rear side) of the metering spline shaft 371 to one side (front side) of the screw 330 . The annular gasket 381 prevents the lubricant supplied to the metering spline shaft 371 and passing through the sliding ring 382 from leaking to the screw 330 side. The lubricant can be supplied to the sliding ring 382 to reduce the sliding resistance of the sliding ring 382 and prevent the lubricant from leaking to the screw 330 side. Here, the lubricant supplied to the metering spline shaft 371 passes through the cracks formed in the sliding ring 382 between the sliding ring 382 and the rotor 343 of the metering motor 340 and between the sliding ring 382 and the screw mounting portion 372 .

The injection molding machine 10 is equipped with a load detector 360 . The load detector 360 detects the load transferred between the injection motor 350 and the screw 330 . The load detector 360 detects the load behind the bearing 361 . The load detector 360 is, for example, a washer type and is arranged between the rear flange 308 and the injection motor 350 .

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

FIG. 6 is a diagram showing the structural elements of the control device 700 according to one embodiment in functional blocks. Each functional block illustrated in FIG. 6 is a conceptual functional block and does not necessarily need to be physically configured as shown. All or part of each functional block can be functionally or physically dispersed/integrated into any unit and configured. All or any part of each processing function performed in each functional block is realized by a program executed by the CPU 701 . Alternatively, each functional block can be implemented as hardware based on wiring 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 detection value of the pressure detected by the load detector 360 based on the speed of the screw 330 , the phase in the axial direction of the screw 330 , and the phase of the metering motor 340 . The acquisition unit 602 acquires various information such as the detection value of the pressure detected by the load detector 360 . The registration unit 603 registers information for causing the correction information storage unit 601 to perform correction based on the information acquired by the acquisition unit 602 . The correction control part 604 corrects the detection value detected by the load detector 360 based on the information stored in the correction information storage part 601, and corrects the pressure setting value used in the pressure control of the screw 330. The display control unit 605 displays the corrected pressure value on the display device 760 . The pressure control unit 606 performs pressure control based on the corrected pressure setting value. In addition, the specific description of each structure will be described later.

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

In the measuring process, the measuring motor 340 is rotationally driven and the screw 330 is rotated. In this way, the thread (thread) of the screw 330 moves, and the resin particles (solid molding material) filled in the thread groove of the screw 330 are transported forward. The resin particles are gradually melted by being heated by heat or the like from the heaters 313_1 to 313_5 passing through the cylinder 310 while moving forward in the cylinder 310 . Then, the resin particles become completely molten in the front end portion of the cylinder 310 . Then, the screw 330 retreats as the liquid molding material (resin) is transported to the front of the screw 330 and accumulated in the front of the cylinder 310 .

The metering motor encoder 341 detects the rotation of the metering motor 340 and sends 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 metering motor encoder 341, and a conventional detector can be used.

Conventionally, friction and eccentric load inside the injection device 300 act on the load detector 360 . When the screw 330 was not mounted on the injection device 300, tests were conducted on the pressure detected by the load detector 360. As a result, it was found that the phase of the metering spline shaft 371, the position of the injection spline shaft 363, and the injection spline depended on the pressure detected by the load detector 360. The detected value of the pressure changes due to the speed of the key shaft 363.

Based on these requirements, even if the detection 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 injection to injection.

FIG. 7 is a conceptual diagram showing the pressure detected by the load detector 360 during measurement in this embodiment. In the example shown in FIG. 7 , arrows indicate forces applied during measurement. For example, let the detection value 1701 be the detection value of the pressure detected by the load detector 360 . However, load detector 360 preferably detects force 1702 caused by resin pressure. However, friction and eccentric load inside the injection molding machine 10 affect the load detector 360 . Therefore, the detection value 1701 is expressed by the following formula (1).

Detection value 1701=force caused by 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 reason why the moment 1704 of the metering spline shaft 371 and the moment 1704 of the metering spline shaft 371 shown in the equation (1) are included in the detection value 1701 is because the load detector 360 also detects the force in the torsional direction.

The first sliding resistance 1703 is, for example, the sliding resistance caused by the metering spline shaft 371 , the annular gasket 381 and the sliding ring 382 . The sliding resistance of the metering spline shaft 371 is generated at the spline connection between the metering spline nut 344 and the metering spline shaft 371 . When the metering spline shaft 371 is eccentric, the contact area between the metering spline shaft 371 and the metering spline nut 344 changes according to the phase of the metering spline shaft 371 . Therefore, the sliding resistance changes depending on the phase of the metering spline shaft 371 . However, the metering spline shaft 371 is coupled to the screw 330 via the bearing frame 370 . Therefore, in other words, the first sliding resistance 1703 changes depending on the position (rotation angle) of the screw 330 in the circumferential direction.

The second sliding resistance 1706 is the sliding resistance caused by the injection spline shaft 363 . That is, the sliding resistance of the second sliding resistance 1706 is generated at the spline connection portion between the metering spline nut 344 , the injection spline shaft 363 and the injection spline nut 354 . When the injection spline shaft 363 is eccentric, the contact area between the injection spline shaft 363 and the injection spline nut 354 changes depending on the phase of the injection spline shaft 363 . Therefore, the second sliding resistance 1706 changes depending on 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 to control the movement of the axial position of the screw 330 . Therefore, in other words, the second sliding resistance 1706 changes depending on the axial position of the screw 330 (the phase of the injection motor 350).

Thus, when the correction value for detecting the force 1702 caused by the resin pressure is generated, it needs to be changed according to the circumferential position (rotation angle) of the screw 330 and the axial position of the screw 330 . In addition, in the example shown in FIG. 7 , the force during measurement is shown, but the force during filling/pressure holding can also be calculated by the same method, so the description is omitted.

FIG. 8 is a diagram illustrating the relationship between the detection value detected by the load detector 360 and the force caused by the resin pressure according to the first embodiment. In the example shown in FIG. 8 , let it be the detection value 1801 detected by the load detector 360 during the measurement, and let it be the resistance 1802 caused by mechanical friction or the like during the measurement. The resistance 1802 includes, in addition to the above-mentioned sliding resistance (for example, the first sliding resistance 1703 and the second sliding resistance 1706), moments (for example, the moment 1704 of the metering spline shaft 371 and the moment 1704 of the injection spline shaft 363).

Since the screw 330 retreats during measurement, 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 caused by mechanical friction or the like during measurement is directed toward The negative direction works. Furthermore, the force 1803 caused by the resin pressure during measurement is derived from the detection value 1801 - the resistance 1802.

In the example shown in FIG. 8 , let it be the detection value 1804 detected by the load detector 360 during filling/maintenance, and let it be the resistance 1805 caused by mechanical friction or the like during filling/maintenance. The resistance 1805 includes torque in addition to the sliding resistance mentioned above.

Since the screw 330 advances during filling/maintenance, when the direction of the detection value 1801 detected by the load detector 360 is set to the positive direction, the resistance 1805 caused by mechanical friction or the like during filling/maintenance is in the positive direction. kick in. The force 1806 caused by the resin pressure during filling/holding is derived based on the detection value 1804-resistance 1805.

As shown in FIG. 8 , the force 1803 caused by the resin pressure during metering is smaller than the force 1806 caused by the resin pressure during filling/holding. In other words, changes in mechanical friction and the like play a large role. The control device 700 of this embodiment can realize highly accurate detection of the force 1803 caused by the resin pressure during such measurement.

Specifically, the circumferential position of the screw 330 , the position of the screw 330 , and the speed of the screw are each set as a variable, and a table that determines the correction value based on the combination of the variables is stored in the correction information storage unit 601 in advance. Then, the correction control unit 604 acquires the correction value from the table in real time, and corrects the detection value of the pressure detected by the load detector 360 . In addition, considering that there are individual differences for each injection device 300, it is possible to register the correction value in the table during the inspection process before shipment or when the user starts molding.

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

The registration unit 603 registers in the correction information storage unit 601 a correction value (an example of correction information) obtained by correcting the detection value of the load detector 360 based on the acquired detection value of the pressure. The correction value in this embodiment is a value indicating the force (resistance) generated due to external disturbance caused by mechanical friction or the like. Furthermore, in this embodiment, the force caused by the resin pressure can be derived by subtracting the correction value from the detection 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 circumferential position of the screw 330 is fixed. The example shown in FIG. 9 shows the variation 901 in the detection 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°. The fluctuation of the detection value 902 when the circumferential position (rotation angle) of the screw 330 is fixed at +180° 903 When the circumferential position (rotation angle) of the screw 330 is fixed at +270° Change in detection value 904.

Furthermore, based on the changes in the detection value 901, 904, etc., it can be confirmed that the detection value of the pressure changes periodically depending on the position of the screw 330. This change in the detection value corresponds to a change in the phase (rotation angle) of the injection spline shaft 363 .

Similarly, the detected pressure value changes depending on the position (rotation angle) of the screw 330 in the circumferential direction. Furthermore, the detected value of the pressure changes according to the speed of the screw 330 .

Therefore, in the present embodiment, the load detector 360 is corrected 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 . detection value.

In this embodiment, a method of creating a table storing correction values in advance is used. In this embodiment, in order to create the correction information storage unit 601 in which correction values are stored, the pressure is detected by the load detector 360 in the injection device 300 without mounting the assembly of the screw 330 . For example, the assembly of the screw 330 can be considered to include a structure including the screw 330, the barrel 315, the cylinder 310 and the nozzle 320. In addition, the environment when performing pressure detection is not limited to when the assembly without the screw 330 is installed, as long as the molding material is not filled and the screw 330 is not in metal contact.

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

FIG. 10 is a diagram illustrating 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 this embodiment can be based on 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 screw. 330 velocities to determine the correction value (force due to resin pressure). In the example shown in FIG. 10 , a table is prepared for each speed of the screw 330 , and the speed of the screw 330 is set to V ₁ <V ₂ <V ₃ <maximum speed.

Furthermore, the correction control unit 604 refers to the correction information storage unit 601, obtains 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, and corrects the detection output from the load detector 360 based on the correction value. value, and determine the corrected detection value.

The display control unit 605 displays the detection value corrected by the correction control unit 604 on the display device 760 as the force caused by the resin pressure.

The pressure control unit 606 performs pressure control so that the detection value corrected by the correction control unit 604 becomes a pressure setting value preset for filling the injection device 300 with the molding material at the time of mold closing or the like. This eliminates the influence of external disturbances such as sliding resistance and torque, thereby improving the accuracy of pressure control.

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. It is assumed that when the correction value is registered as shown in FIG. 11 , the assembly of the screw 330 is not mounted.

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

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

The acquisition unit 602 acquires the detection value detected by the load detector 360 during stroke control (step 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 when the detection value is detected, the speed of the screw 330 and the circumferential position, and registers the correction value in the correction value. Information storage unit 601 (step S1104).

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

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

On the other hand, when it is determined that the registration unit 603 has registered the correction values for all positions in the circumferential direction of the screw 330 (step S1105: YES), the registration unit 603 determines whether the correction values have been registered for all the speeds of the screw 330 (step S1105: YES). S1107).

When it is determined that the registration unit 603 has not registered correction values for all the speeds of the screw 330 (step S1107: No), the speed of the screw 330 is changed (step S1108). In addition, the speed of the screw 330 is changed according to the operation of the injection motor 350 .

On the other hand, when it is determined that the registration unit 603 has registered the correction values for all the speeds of the screw 330 (step S1108: “Yes”), the process ends.

Through the above-described processing steps, the registration of the correction value in the correction information storage unit 601 is completed.

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

First, the acquisition unit 602 acquires the detection value of the pressure detected by the load detector 360 during stroke control (step S1201). Furthermore, the acquisition unit 602 acquires the current speed of the screw 330, the circumferential position of the screw 330, and the current speed of the screw 330 based on the detection results of various sensors (for example, the metering motor encoder 341 and the injection motor encoder 351) provided in the injection device 300. The axial position of the screw 330 (step S1202).

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

Then, the correction control unit 604 subtracts the correction value from the detection value to derive a corrected detection value.

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

In this embodiment, by performing the above-mentioned processing steps, it is possible to detect the force caused by the resin pressure while suppressing the influence of external interference such as mechanical friction during measurement.

Furthermore, in the example shown in FIG. 12 , the method of detecting the force caused by the resin pressure based on the detection value detected by the load detector 360 during measurement has been explained. However, the detection of the force caused by the resin pressure is not limited to the time of metering. For example, the force caused by the resin pressure may be detected based on the detection value 804 detected by the load detector 360 at the time of filling/holding pressure.

When filling/maintaining pressure, the pressure control unit 606 performs pressure control so that the correction value acquired by the correction control unit 604 becomes a pressure set value preset for filling the injection device 300 with the molding material.

Furthermore, in the present embodiment, an example is described in which the detection value detected by the load detector 360 is corrected with reference to the correction information storage unit 601 . However, in this embodiment, the object to be corrected is not limited to the detection value, and the pressure setting used for pressure control can also be corrected.

At this time, the correction information storage unit 601 stores a pressure setting value 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. Furthermore, the pressure control unit 606 performs pressure control so that the detection value acquired by the acquisition unit 602 becomes a pressure setting value that takes into consideration external disturbances such as mechanical resistance.

(Second Embodiment)

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

As shown in Figure 9 and others, the force caused by external disturbance changes periodically. For example, the detected value of the pressure changes periodically according to the position of the screw 330 based on the changes in the detected value 901, 904, etc. This change in the detection value corresponds to a change in the phase (rotation angle) of the injection spline shaft 363 . Similarly, changes in the detection value occur in response to changes in the phase of the metering spline shaft 371 . Therefore, by mathematically modeling the periodic changes in each requirement, the correction value corresponding to the external disturbance requirement can be determined based on the mathematical model.

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

Therefore, the sin function 1002 corresponding to the variation 1301 of resistance including friction and the like can be derived. At this time, the following formula (2) can be derived. In addition, the phase θ _offset is set to a phase offset corresponding to the actual friction variation of the injection device 300 . The variable k is a coefficient corresponding to the actual variation range of the injection device 300 . Furthermore, the phase θ is set to the phase of the injection spline shaft 363 that moves the circumferential position (rotation angle) of the screw 330 or the position of the screw 330 .

Correction value for each requirement = k·sin ² ((θ-θ _offset )/2)......(2)

Furthermore, by combining an equation representing a correction value corresponding to the position (rotation angle) in the circumferential direction of the screw 330 and an equation 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 mathematical expression for calculating a correction value (hereinafter also referred to as a position correction value) related to a position. Furthermore, by combining a mathematical expression capable of calculating a correction value related to a position and a correction value corresponding to the speed of the screw 330 (hereinafter referred to as a speed correction value), a mathematical expression model for calculating the correction value can be realized.

Specifically, the registration unit 603 registers each value of the following equation (3) (k, θ _{ij_offset} , θ _{rt_offset} , and a table of speed correction values Pv) in the correction information storage unit 601 . The variable k is a coefficient corresponding to the actual variation range of the injection device 300 . Furthermore, the phase θ _ij is the phase of the injection motor 350 (injection spline shaft 363 ) that moves in the axial direction of the screw 330 . The correspondence between the phase θ _ij (angle) of the injection motor 350 and the position of the screw 330 can be derived from the correspondence between the rotation angle of the injection motor 350 and the movement amount of the screw 330, and therefore the description is omitted. Let the phase θ _rt be the position (rotation angle) of the screw 330 in the circumferential direction. The phase θ _{ij_offset} is set to a phase offset corresponding to the actual change in the axial position of the screw 330 (the phase of the injection motor 350 ). The phase θ _{rt_offset} is set to a phase offset corresponding to an actual change in the position (rotation angle) of the screw 330 in the circumferential direction. The table of the speed correction value 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 a speed correction value storage table stored in 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 speed in the axial direction of the screw 330 .

In addition, as shown in the flowchart of FIG. 11 of the first embodiment, the speed correction value Pv and the variable k are detected by changing the speed and circumferential position of the screw 330 while obtaining detection of each position in the axial direction of the screw 330 value, so description is omitted. In addition, the period of phase θ _ij and the phase θ _{ij_offset} can be derived from the period and phase of the injection motor 350 . Likewise, the period of phase θ _rt and the phase θ _{rt_offset} can be derived based on the period and phase of metering motor 340 . Thus, the correction value can be derived based on equation (3).

FIG. 15 is a diagram illustrating the variation of the correction value calculated by the correction control unit 604 using equation (3). Periods 1551, 1552, 1553, 1554, and 1555 in FIG. 15 represent the rotation periods of the injection motor 350.

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

In this way, the correction control unit 604 of this embodiment uses 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 speed of the screw, and performs the calculation based on Equation (3) calculates the correction value.

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. The subsequent processing is the same as that of the above-mentioned embodiment, so the description is omitted.

(Third Embodiment)

In the above-mentioned embodiment, the example in which the table is referenced when determining the correction value has been explained. However, the above-described embodiment is not limited to the method of referring to the table. In the third embodiment, a method of calculating correction values using only a mathematical model is adopted.

In the second embodiment, the speed correction value storage table is used. However, instead of the speed correction value Pv acquired from the speed correction value storage table, the equation for calculating the speed correction value based on the speed is substituted into the position of the speed correction value Pv in equation (3). , whereby the correction value can be calculated using only the mathematical model.

For example, in a normal injection device, when the speed of the screw 330 is '0', it is a resistance value such as mechanical friction. In other words, as the speed correction value becomes the maximum and the speed of the screw 330 becomes larger, the resistance value (speed correction value) become smaller. If the speed of the screw 330 reaches a predetermined value, the relationship between speed and friction is considered to be a linear transition, and the speed correction value can be linearly changed with respect to the speed. Since the change is small compared to static friction, it can be treated as constant. By substituting such a change in the speed correction value into equation (3) as a mathematical expression, the correction value can be calculated using only the mathematical model.

As in the above embodiment, the combination of tables and mathematical models differs depending on the embodiment. For example, when it is judged that the calculation time is long, you can consider using a table, and when you want to reduce the storage capacity, you can consider using a mathematical model.

The above embodiment describes the method of determining the correction value in a state where the assembly of the screw 330 is not mounted, but the method of determining the correction value is not limited. For example, when the screw 330 is mounted, the correction value can be determined by filling the cylinder 310 with resin and raising the temperature, and then operating the screw 330 at a low speed. At this time, only a correction value based on the resistance at low speed can be determined. However, as the speed of the screw 330 becomes faster, the resistance value tends to decrease, so a correction value corresponding to the speed can be estimated.

(Modification)

The above embodiment has described an example in which the correction control unit 604 corrects the detection value output from the load detector 360 based on a combination of the circumferential position of the screw 330, the position of the screw 330, and the speed of the screw. However, the above-described embodiment is not limited to the method of determining the correction value based on a 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 unit 604 may determine 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 may determine a pressure setting value determined based on the circumferential position of the screw 330 and a combination of the position of the screw 330 , and the pressure control unit 606 may perform pressure control according to the determined pressure setting value. In addition, a table or a mathematical model may be used to determine the correction value or the pressure setting value based on the circumferential position of the screw 330 and a combination of the position of the screw 330 .

As another example, the correction control unit 604 may determine 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 part 604 may determine a pressure setting value determined based on a combination of the circumferential position of the screw 330 and the speed of the screw 330, and the pressure control part 606 may perform pressure control according to the determined pressure setting value.

As another example, the correction control unit 604 may determine the correction value based on a combination of the axial position of the screw 330 and the speed of the screw 330 . Furthermore, the correction control part 604 may determine a pressure setting value determined based on a combination of the axial position of the screw 330 and the speed of the screw 330, and the pressure control part 606 may perform pressure control according to the determined pressure setting value.

In this way, even when the correction value or the pressure setting value is determined based on the position of the screw 330 in the circumferential direction and a combination of two requirements: the position of the screw 330 and the speed of the screw, the determined correction value can be used. By correcting the detection value or using the corrected pressure setting value for pressure control, detection accuracy and pressure control accuracy can be improved.

Furthermore, the method of determining the correction value is not limited to a combination of two or more requirements, and the correction value may be determined based on one requirement. For example, the correction value and the pressure setting value may be determined based on the position of the screw 330 in the circumferential direction. Furthermore, the correction value and the pressure setting value can be determined based on the axial position of the screw 330 . Furthermore, the correction value and the pressure setting value may also be determined based on the speed of the screw 330 .

In the above embodiments and modifications, the accuracy of pressure control in the injection/measurement process is improved, and the variation in the detected value of the force caused by the resin pressure between injections can be reduced. This makes it possible to improve the pressure control for filling the molding material and the accuracy of detecting the force caused by the resin pressure.

As mentioned above, the embodiment of the injection molding machine according to the present invention has been described, but the present invention is not limited to the above-mentioned embodiment and the like. Within the scope described in the technical solution, various changes, modifications, replacements, additions, deletions and combinations can be made. Of course, these are also within 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 content of this Japanese Patent Application is incorporated by reference into this specification.

Symbol Description

10-Injection molding machine, 300-Injection device, 330-Screw, 340-Measuring motor, 350-Injection motor, 700-Control device, 601-Calibration information storage unit, 602-Acquisition unit, 603-Registration unit, 604-Calibration Control part, 605-display control part, 606-pressure control part.

Claims (6)

1. An injection molding machine having: An injection device for filling the mold device with molding material; and a control device to control said injection device, The injection device has a cylinder for heating the molding material, a screw disposed in the cylinder, and a metering motor for rotating the screw, The control device has: A correction control unit corrects a pressure setting value used for pressure control of the screw or corrects an action on the screw based on the circumferential position of the screw that changes with the operation of the metering motor. The detection value of the pressure output by the pressure detector. 2. The injection molding machine according to claim 1, wherein, The control device also has: a storage unit that stores correction information corresponding to the position of the screw in the circumferential direction, The correction control unit corrects the pressure setting value used in the pressure control of the screw or corrects a pressure detector that detects the pressure acting on the screw based on the correction information corresponding to the position in the circumferential direction. Output detection value. 3. An injection molding machine having: An injection device for filling the mold device with molding material; and a control device to control said injection device, The injection device includes a cylinder that heats the molding material, a screw disposed in the cylinder, and an injection motor that moves the screw, The control device has: The correction control unit corrects the pressure setting value used in the pressure control of the screw based on the axial position of the screw that changes with the operation of the injection motor or corrects the pressure acting on the screw from detection. The detection value output by the pressure detector of the screw pressure. 4. The injection molding machine according to claim 3, wherein, The control device also has: a storage unit that stores correction information corresponding to the position of the screw in the axial direction, The correction control unit corrects the pressure setting value used in the pressure control of the screw or corrects the pressure detection from detecting the pressure acting on the screw based on the correction information corresponding to the position in the axial direction. The detection value output by the detector. 5. An injection molding machine having: An injection device for filling the mold device with molding material; and a control device to control said injection device, The injection device includes a cylinder that heats the molding material, a screw disposed in the cylinder, and an injection motor that moves the screw, The control device has: The correction control unit corrects the pressure setting value used for the pressure control of the screw based on the speed of the screw that changes with the operation of the injection motor or corrects the pressure from detecting the pressure acting on the screw. The detection value output by the pressure detector. 6. The injection molding machine according to claim 5, wherein, The control device also has: a storage unit that stores correction information corresponding to the speed of the screw, The correction control unit corrects a pressure setting value used in pressure control of the screw or corrects an output from a pressure detector that detects the pressure acting on the screw based on the correction information corresponding to the speed of the screw. detection value.